Health & Fitness Calculators
Simple tools to help with fitness, nutrition and everyday wellness calculations.
Pace Calculator
Calculate your pace, speed and estimated finish times for popular race distances.
Calculate your pace →Treadmill Pace Calculator
Convert treadmill speed (mph or km/h) into running pace and back. Estimate 5K and 10K finish times, compare incline effort, and print pace charts.
Calculate treadmill pace →Pregnancy Weight Gain Calculator
Estimate a healthy pregnancy weight-gain range based on pre-pregnancy BMI and current week.
Calculate weight gain →Ovulation Calculator
Estimate ovulation dates, fertile windows, upcoming menstrual cycles, and your next expected period.
Calculate fertile window →Calorie Deficit Calculator
Estimate daily maintenance calories, compare calorie deficit percentages, and calculate an illustrative daily calorie target.
Calculate calorie deficit →Body Fat Percentage Calculator
Estimate body fat percentage using simple body measurements. Calculate estimated fat mass and fat-free mass with the U.S. Navy circumference method.
Calculate body fat →Macro Calculator
Calculate daily protein, carbohydrate, and fat goals based on your calorie needs. Choose balanced, higher-protein, or custom macro percentages.
Calculate your macros →TDEE Calculator
Estimate your Total Daily Energy Expenditure and maintenance calories using age, height, weight, and activity level. Compare daily and weekly calorie estimates.
Calculate your TDEE →Sleep Calculator
Find suggested bedtimes or wake-up times based on complete sleep cycles.
Plan my sleep →Water Intake Calculator
Estimate a practical daily hydration target based on your weight, activity and lifestyle.
Calculate water intake →BMI Calculator
Estimate Body Mass Index, weight category and a healthy weight range.
Calculate BMI →Calorie Calculator
Estimate BMR, maintenance calories, and daily calorie targets for weight loss or gain.
Calculate calories →Age Calculator
Calculate your exact age and see the time until your next birthday.
Calculate age →❤️ Free Health & Fitness Calculators for Everyday Wellness
Welcome to MyCruncher’s collection of free Health & Fitness Calculators, designed to make common fitness, nutrition, body-measurement, and wellness calculations easier to understand.
Whether you want to estimate daily calories, calculate BMI, explore body fat percentage, plan macronutrients, check running pace, or estimate sleep and hydration needs, you’ll find tools for a variety of everyday questions.
Our expanded collection also includes calculators for menstrual-cycle planning, ovulation estimates, pregnancy dates, and pregnancy weight-gain reference information.
Each tool focuses on a specific calculation and provides results based on the measurements, dates, or other values you enter.
🧮 Which Health & Fitness Calculator Should You Use?
Different calculators answer different questions. Use this guide to find the best starting point for the information you want to estimate.
| Your Question | MyCruncher Calculator |
|---|---|
| What is my Body Mass Index? | BMI Calculator |
| What is my estimated body fat percentage? | Body Fat Percentage Calculator |
| How many calories might I need each day? | Calorie Calculator |
| How many calories do I use at my activity level? | TDEE Calculator |
| How does a percentage calorie deficit work? | Calorie Deficit Calculator |
| How many grams of protein, carbs and fat? | Macro Calculator |
| What is my running or walking pace? | Pace Calculator |
| What is an estimated daily hydration amount? | Water Intake Calculator |
| What bedtime or wake-up time should I plan? | Sleep Calculator |
| How old am I in years, months and days? | Age Calculator |
| When might I ovulate or have my next period? | Ovulation Calculator |
| What is my estimated pregnancy due date? | Pregnancy Due Date Calculator |
| How do general pregnancy weight-gain ranges work? | Pregnancy Weight Gain Calculator |
All these tools are available online without requiring a separate calculator app.
⚖️ BMI Calculator — Understanding Body Mass Index
Body Mass Index, or BMI, is a screening measurement that compares body weight with height.
It is commonly used in adult weight-status screening, but it does not directly measure body fat, muscle mass, or overall health.
How to Calculate BMI
Worked BMI Example
Suppose an adult weighs 70 kilograms and is 1.75 meters tall.
First, square the height:
1.75 × 1.75 = 3.0625
Then divide weight by the squared height:
70 ÷ 3.0625 ≈ 22.86
This is a mathematical example, not an individual health assessment.
Adult BMI Screening Categories
| BMI | Adult Screening Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 to less than 25 | Healthy weight |
| 25 to less than 30 | Overweight |
| 30 or greater | Obesity |
These CDC categories are intended for general adult screening, not for diagnosing disease. BMI interpretation is different for children, teenagers, and pregnancy.
Use the MyCruncher BMI Calculator to calculate BMI from your height and weight.
💪 Body Fat Percentage Calculator — Tape-Measurement Estimates
Body fat percentage describes the estimated proportion of total body weight made up of fat.
Unlike BMI, a body fat percentage estimate attempts to describe body composition. However, tape-based methods do not directly measure body fat either.
How the Navy Circumference Method Works
MyCruncher’s Body Fat Percentage Calculator uses traditional U.S. Navy circumference equations.
The male-based formula uses height, neck, and abdominal circumference.
The female-based formula uses height, neck, natural waist, and hip circumference.
| Formula Variant | Required Measurements |
|---|---|
| Male-based | Height, neck, abdomen at navel |
| Female-based | Height, neck, natural waist, hips |
The calculator supports inches and centimeters. Metric values are converted before evaluating the traditional equations.
What Is Fat-Free Mass?
Fat-free mass is the estimated weight of everything not counted as body fat.
It includes muscle, bone, organs, water, and other tissues. It is not the same as muscle mass.
Body Composition Example
Suppose someone weighs 180 pounds and has an estimated body fat percentage of 17.5%.
180 × 0.175 = 31.5 pounds
🔥 Calorie Calculator — Estimating Daily Energy Needs
Your body uses energy for essential functions, movement, exercise, and processing food.
The number of calories needed per day varies between individuals.
Age, height, weight, body composition, activity level, and other physiological factors can affect energy requirements.
What Does the Calorie Calculator Estimate?
The MyCruncher Calorie Calculator provides energy estimates based on its selected personal measurements and activity assumptions.
It can help visitors explore maintenance calories and general calorie-planning scenarios.
Resting Calories vs. Daily Calories
Resting energy expenditure estimates calories used while the body is at rest.
Total daily energy expenditure includes resting energy as well as estimated activity and other daily energy needs.
Different formulas and activity assumptions may produce different results for the same person.
Calorie estimates should not be treated as measured requirements or guaranteed weight management outcomes.
🚶 TDEE Calculator — Total Daily Energy Expenditure
TDEE stands for Total Daily Energy Expenditure.
It represents an estimate of the energy your body uses throughout a typical day.
MyCruncher’s TDEE Calculator uses the Mifflin–St Jeor equation to estimate resting energy, then applies an approximate activity multiplier.
TDEE Formula
Activity Multipliers Used by MyCruncher
| Activity Level | Multiplier |
|---|---|
| Mostly sitting | 1.20 |
| Lightly active | 1.375 |
| Moderately active | 1.55 |
| Very active | 1.725 |
| Extremely active | 1.90 |
Worked TDEE Example
Consider the following example measurements:
- Age: 35 years
- Weight: 175 pounds
- Height: 5 feet 8 inches
- Female-based equation
- Lightly active
The Mifflin–St Jeor equation produces an estimated resting energy of approximately 1,537 calories per day.
Multiply by 1.375:
This represents an illustrative maintenance estimate, not an individualized diet recommendation.
Daily vs. Weekly TDEE
The calculator also provides an estimated weekly energy total by multiplying daily TDEE by seven.
That result is a simplified seven-day estimate, not a weight-change prediction.
📉 Calorie Deficit Calculator — Comparing Daily Calorie Targets
A calorie deficit occurs when energy intake is lower than energy use over time.
The Calorie Deficit Calculator lets visitors compare maintenance calories with selected percentage reductions.
Its available options include maintenance, 10%, 15%, and 20% reductions.
Calorie Deficit Formula
Example: 2,300 Maintenance Calories
| Selected Option | Calorie Difference | Illustrative Intake |
|---|---|---|
| Maintenance — 0% | 0 calories | 2,300 calories |
| 10% reduction | 230 calories | 2,070 calories |
| 15% reduction | 345 calories | 1,955 calories |
| 20% reduction | 460 calories | 1,840 calories |
Worked 15% Example
Suppose the starting maintenance estimate is 2,300 calories.
2,300 × 0.15 = 345 calories.
2,300 − 345 = 1,955 calories.
🥗 Macro Calculator — Protein, Carbohydrates & Fat
Macronutrients are nutrients the body uses in relatively large amounts.
The three calculated by MyCruncher are carbohydrates, protein, and fat.
The Macro Calculator converts daily calories and selected percentages into estimated grams of each macronutrient.
Calories Per Gram
| Macronutrient | Approximate Calories per Gram |
|---|---|
| Carbohydrates | 4 |
| Protein | 4 |
| Fat | 9 |
How to Calculate Macro Grams
Example: 2,000 Calories
The Balanced preset uses 50% carbohydrates, 20% protein, and 30% fat.
| Macro | Percentage | Daily Grams |
|---|---|---|
| Carbohydrates | 50% | 250 g |
| Protein | 20% | 100 g |
| Fat | 30% | 66.7 g |
Other Macro Presets
MyCruncher also provides a Higher Protein preset and a Higher Carbohydrate preset.
| Preset | Carbs | Protein | Fat |
|---|---|---|---|
| Balanced | 50% | 20% | 30% |
| Higher Protein | 45% | 30% | 25% |
| Higher Carbohydrate | 55% | 20% | 25% |
General Adult Macronutrient Reference Ranges
The National Academies’ Acceptable Macronutrient Distribution Ranges provide broad adult references.
| Macronutrient | Adult Reference Range |
|---|---|
| Carbohydrates | 45–65% of total energy |
| Protein | 10–35% of total energy |
| Fat | 20–35% of total energy |
These ranges are not personalized diet prescriptions. Meeting three macro percentages does not automatically ensure a nutritionally complete eating pattern.
🏃 Pace Calculator — Running, Walking & Finish Times
Pace describes how much time it takes to cover a unit of distance.
Running and walking pace is commonly shown in minutes per mile or minutes per kilometer.
The Pace Calculator can estimate average pace, speed, and illustrative finish times.
Running Pace Formula
Worked Pace Example
Suppose someone runs three miles in 30 minutes.
30 minutes ÷ 3 miles = 10 minutes per mile.
Running Pace Comparison
| Average Pace | Time for 3 Miles |
|---|---|
| 7:00 per mile | 21 minutes |
| 8:00 per mile | 24 minutes |
| 9:00 per mile | 27 minutes |
| 10:00 per mile | 30 minutes |
| 11:00 per mile | 33 minutes |
| 12:00 per mile | 36 minutes |
These calculations assume a steady average pace. Real-world performance may vary because of terrain, fatigue, weather, stops, and other factors.
💧 Water Intake Calculator — General Hydration Estimates
Water supports normal body functions, including temperature regulation, circulation, and fluid balance.
The Water Intake Calculator provides an illustrative daily hydration estimate based on its inputs.
Individual fluid needs can vary with activity, climate, diet, age, and medical circumstances.
Some water also comes from foods and other beverages.
Water Measurement Conversions
| Volume | Approximate Milliliters |
|---|---|
| 1 US fluid ounce | 29.57 mL |
| 1 US cup | 237 mL |
| 2 US cups | 473 mL |
| 4 US cups | 946 mL |
| 8 US cups | 1,893 mL |
😴 Sleep Calculator — Bedtime & Wake-Up Planning
Sleep plays an important role in overall health, daily functioning, and well-being.
The Sleep Calculator can help visitors plan possible bedtime and wake-up times using its sleep-cycle assumptions.
The CDC recommends that most adults aged 18–60 obtain at least seven hours of sleep per night.
Sleep needs vary by age and individual. Sleep quality and consistency also matter.
Sleep Duration Example
Suppose a person goes to bed at 10:30 PM and gets out of bed at 6:30 AM.
Actual time asleep may be shorter because of time taken to fall asleep or periods of wakefulness.
🌸 Ovulation Calculator — Fertile Window & Period Estimates
The Ovulation Calculator estimates menstrual cycle dates using the first day of the last period and the selected average cycle length.
It provides an estimated ovulation date, fertile window, next expected period, and future cycle projections.
Understanding Cycle Timing
A menstrual cycle is counted from the first day of one period to the first day of the next.
Ovulation commonly occurs around 14 days before the start of the next menstrual period, although timing varies.
A calendar method uses assumptions about cycle timing. It cannot confirm that ovulation occurred on a particular date.
Why Does the Fertile Window Include Several Days?
Pregnancy can be possible from intercourse before ovulation because sperm may survive for several days.
Actual fertile timing cannot be established with certainty from a basic calendar estimate.
🤰 Pregnancy Due Date Calculator
A pregnancy due date is an estimated date rather than a guarantee of when delivery will occur.
The Pregnancy Due Date Calculator helps estimate a due date and general pregnancy milestones.
How Is a Due Date Commonly Estimated?
One conventional method counts approximately 40 weeks, or 280 days, from the first day of the last menstrual period.
This is a general dating convention that assumes typical cycle timing.
A prenatal care professional may establish or confirm the clinical due date using ultrasound and other medical information.
💕 Pregnancy Weight Gain Calculator — General Reference Ranges
Pregnancy weight-gain guidance may depend on prepregnancy BMI, the number of babies, pregnancy stage, and individual medical circumstances.
MyCruncher’s Pregnancy Weight Gain Calculator uses entered measurements and pregnancy information to provide general reference estimates.
General US Reference Ranges for One Baby
The CDC publishes general pregnancy weight-gain ranges based on prepregnancy BMI for a pregnancy with one baby.
| Prepregnancy BMI | General Total Gain Range |
|---|---|
| Below 18.5 | 28–40 lb |
| 18.5 to less than 25 | 25–35 lb |
| 25 to less than 30 | 15–25 lb |
| 30 or greater | 11–20 lb |
These are broad reference ranges, not recommendations for a particular pregnancy.
Different guidance applies to pregnancies involving twins or other multiples.
🎂 Age Calculator — Calendar Age & Birthday Planning
The Age Calculator provides calendar age based on an entered birth date and reference date.
It can help with birthday countdowns, age comparisons, and everyday date calculations.
Calendar Age vs. Biological Age
Calendar age is the amount of time that has elapsed since birth.
It does not represent a measured biological or medical fitness age.
Simple Age Example
Suppose someone was born on July 1, 2000.
On July 1, 2026, their calendar age would be:
📋 How to Use MyCruncher Health & Fitness Calculators
- Choose the right tool. Start with the question you want to answer.
- Read the calculator’s purpose. Check what it estimates and whether it is intended for your situation.
- Enter accurate information. Double-check measurements, dates, units, and activity choices.
- Calculate the result. Review the estimate, comparison, or calculated value.
- Read the explanation. Understand the assumptions and limitations behind the result.
- Compare scenarios carefully. Where supported, adjust inputs to see how the calculation changes.
- Seek individual guidance. Discuss medical or nutritional decisions with an appropriately qualified healthcare professional.
Common Mistakes to Avoid
- Mixing pounds and kilograms
- Mixing miles and kilometers
- Using incorrect dates or cycle lengths
- Treating BMI as a medical diagnosis
- Assuming a body fat estimate is exact
- Overestimating activity level for TDEE
- Assuming a calorie deficit guarantees weight loss
- Confusing fat-free mass with muscle mass
- Assuming a hydration estimate fits everyone
- Using ovulation predictions as contraception
- Using pregnancy estimates instead of prenatal care
❓ Health & Fitness Calculator FAQs
Are MyCruncher Health & Fitness Calculators free?
Yes. MyCruncher offers free online calculators for general wellness, nutrition, fitness, body measurements, and date planning.
Which calculator should I use for daily calories?
Use the Calorie Calculator for general calorie estimates or the TDEE Calculator to explore daily maintenance energy and activity factors.
What is the difference between BMI and body fat percentage?
BMI compares weight with height, while body fat percentage estimates the proportion of body weight made up of fat. Neither directly diagnoses health.
Does BMI directly measure body fat?
No. BMI uses height and weight. It does not distinguish between muscle, bone, fat, and other tissues.
What is TDEE?
TDEE means Total Daily Energy Expenditure. It estimates energy used during a typical day, including resting functions and activity.
Is TDEE the same as BMR?
No. BMR refers to energy requirements under controlled basal conditions. TDEE includes estimated daily energy use.
What is the Mifflin–St Jeor equation?
It is a published equation used to estimate resting energy expenditure from age, height, weight, and a sex-specific formula variant.
Can a calorie deficit calculator tell me exactly how fast I will lose weight?
No. A percentage calculation cannot guarantee a particular weight-loss rate. Actual energy needs and physiological responses vary.
How does a Macro Calculator work?
A Macro Calculator divides a selected calorie amount among carbohydrates, protein, and fat, then converts those calorie portions into estimated grams.
How many calories are in protein, carbs and fat?
Standard calculation factors are about 4 calories per gram for protein and carbohydrates, and 9 calories per gram for fat.
Can I enter custom macro percentages?
Yes. The MyCruncher Macro Calculator allows custom percentages that must total 100%. It also offers preset distributions.
Does body fat percentage tell me how much muscle I have?
No. Estimated fat-free mass includes muscle, but also bone, water, organs, and other tissues.
How do I calculate running pace?
Divide total elapsed time by distance. For example, 30 minutes for three miles equals 10 minutes per mile.
Can the Pace Calculator estimate race finish times?
Yes. It can calculate illustrative finish times from an average pace, but actual performance may differ.
How much water should I drink per day?
Water needs vary with activity, environment, diet, age, and health. A general calculator cannot determine everyone’s individual fluid requirement.
How much sleep do adults usually need?
The CDC recommends at least seven hours for most adults aged 18–60. Individual needs and sleep quality also matter.
Does a Sleep Calculator guarantee better sleep?
No. It helps plan possible sleep and wake times but does not guarantee sleep quality or a particular sleep pattern.
Can an Ovulation Calculator confirm when ovulation happens?
No. A basic calendar calculator estimates timing from cycle information. It cannot confirm actual ovulation.
Can an Ovulation Calculator be used to avoid pregnancy?
No. MyCruncher’s simple calendar estimates should not be relied upon as contraception or as guaranteed safe days.
How is a pregnancy due date commonly calculated?
One common approach adds 280 days to the first day of the last menstrual period. Clinical dating may differ.
Are pregnancy weight-gain ranges the same for everyone?
No. General reference ranges depend partly on prepregnancy BMI and pregnancy type. Individual guidance should come from a prenatal care professional.
Can I use these calculators on a mobile phone?
Yes. MyCruncher’s calculator pages are designed for desktop and mobile browsers.
Can I share my calculator results?
Many individual MyCruncher calculators offer Share Result. Some shared links contain entered personal information, so review and share those links carefully.
Who creates MyCruncher calculators?
MyCruncher was founded by Bobby Dues. Learn more on the Meet the Creator section of our About page.
Do these calculators replace professional medical advice?
No. They provide general educational estimates and calculations, not diagnoses, treatment plans, or individualized medical or nutrition advice.
📚 Health & Fitness Information Sources
MyCruncher uses formulas, reference values, and educational explanations where appropriate to each calculator.
The following sources provide additional information about health measurements, nutrition, sleep, and pregnancy.
- CDC — Adult BMI Categories
- Mifflin–St Jeor — Original Resting Energy Equation
- NIH/NIDDK — Body Weight Planner
- National Academies — Macronutrient Reference Ranges
- CDC — About Sleep
- ACOG — Fertility Awareness
- ACOG — Pregnancy Due Dates
- CDC — Pregnancy Weight Gain
- National Library of Medicine — MedlinePlus
MyCruncher is an independent calculator website and is not affiliated with these government agencies or medical organizations.