Health Tools

Health & Fitness Calculators

Free calculators for BMI, daily calorie needs, ideal weight, pregnancy due dates, and more — with plain-language explanations of every result.

Each tool uses evidence-based formulas (WHO, CDC, and clinical standards) and explains what your numbers mean in context. Results are for general informational purposes — consult a healthcare provider for medical decisions.

Body Composition & Weight

Understand your weight, body fat, and healthy ranges

Most Used

BMI Calculator

Calculate your Body Mass Index using height and weight — includes BMI category, healthy range, and what your score means.

Healthy weight checkBMI categoryAdult & child

Calorie Calculator

Find your daily calorie needs based on age, gender, weight, height, and activity level — for weight loss, maintenance, or gain.

Weight lossMuscle gainTDEE / BMR

Ideal Weight Calculator

Estimate your ideal weight range using four evidence-based formulas — Hamwi, Devine, Robinson, and Miller methods.

Healthy range4 formulas comparedBy height

Body Type Calculator

Identify your body shape — ectomorph, mesomorph, or endomorph — based on measurements, and understand what it means for fitness.

Ecto / Meso / EndoFitness tipsBody shape

Bra Size Calculator

Find your correct bra size using band and bust measurements — supports US, UK, EU, and international sizing standards.

US / UK / EU sizesBand + cup sizeInternational sizing

Reproductive Health

Pregnancy planning, due dates, and cycle tracking

Sensitive

Pregnancy Calculator

Calculate your estimated due date, current week of pregnancy, and key milestones — based on last menstrual period or conception date.

Due dateWeek by weekTrimester tracker

Sensitive

Ovulation Calculator

Estimate your ovulation date and fertile window based on your cycle length — helps with conception planning or cycle tracking.

Fertile windowConception planningCycle tracking

How these calculators work

Every tool uses established clinical and scientific formulas. Results include explanations so you understand what the numbers mean.

Evidence-based formulasBMI uses WHO standards. Calorie estimates use Mifflin-St Jeor. Ideal weight uses Devine, Robinson, Hamwi, and Miller methods.

Results in plain languageEvery calculation includes an explanation of what the number means — not just the result. No medical jargon without context.

For general information onlyThese tools are health screening aids, not medical devices. Always consult a qualified healthcare provider for diagnosis or treatment.

Free, private, no loginNo account required, no data stored, no usage limits. Calculations happen in your browser.

Frequently Asked Questions

Common questions about health calculations and how to use these tools.

What is a healthy BMI range for adults?

For most adults, a BMI between 18.5 and 24.9 is considered healthy. A BMI below 18.5 is classified as underweight, 25–29.9 as overweight, and 30 or above as obese. BMI is a screening tool, not a medical diagnosis — factors like muscle mass and bone density can affect its accuracy. Always consult a healthcare provider for a full health assessment.

How many calories should I eat per day to lose weight?

A common starting point is to eat 500 fewer calories than your Total Daily Energy Expenditure (TDEE). For most adults, this creates a deficit that leads to approximately 0.5 kg (1 lb) of weight loss per week. The Calorie Calculator estimates your TDEE based on your age, weight, height, and activity level. Very low-calorie diets (below 1200 for women or 1500 for men) should only be followed under medical supervision.

How do I calculate my pregnancy due date?

The most common method is Naegele's Rule: add 280 days (40 weeks) to the first day of your last menstrual period (LMP). The Pregnancy Calculator does this automatically and also shows your current trimester, week number, and key development milestones. Note that only about 5% of babies are born exactly on the estimated due date — a range of two weeks either side is considered normal.

What is TDEE and how is it different from BMR?

BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest — just to keep your organs functioning. TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor to account for exercise and daily movement. For weight management, TDEE is the more useful number because it reflects your real-world calorie needs.

Which ideal weight formula is most accurate?

No single formula is universally accurate — each was developed for different populations and purposes. The Devine formula is most commonly used in medical settings (originally for drug dosing). The Robinson and Miller formulas are slight refinements. The Ideal Weight Calculator shows all four alongside each other so you can see the range rather than relying on a single number.

Are these health calculators suitable for children?

The BMI Calculator includes a mode for children and teens (ages 2–19) using CDC growth chart percentiles, which is the correct method for minors — adult BMI ranges do not apply to children. The Calorie and Ideal Weight calculators are designed for adults. For child-specific health assessments, always consult a pediatrician.

Which bra size standards does the Bra Size Calculator support?

The Bra Size Calculator supports US (34B, 36C), UK (34B, 36C — same letters but different cup sizing), EU/European (75B, 80C), and international sizing standards. Enter your underbust measurement (band size) and your overbust measurement (bust size), and it converts to all major sizing systems simultaneously so you can shop from any international retailer.

Tool Journey

Every calculator added to this module, organized by year and month.

20263 tools

Feb 20261 added

Pregnancy Calculator

Calculate your estimated due date, current week of pregnancy, and key milestones — based on last menstrual period or conception date.

Jan 20262 added

Body Type Calculator

Identify your body shape — ectomorph, mesomorph, or endomorph — based on measurements, and understand what it means for fitness.

Bra Size Calculator

Find your correct bra size using band and bust measurements — supports US, UK, EU, and international sizing standards.

20254 tools

Dec 20252 added

Ideal Weight Calculator

Estimate your ideal weight range using four evidence-based formulas — Hamwi, Devine, Robinson, and Miller methods.

Ovulation Calculator

Estimate your ovulation date and fertile window based on your cycle length — helps with conception planning or cycle tracking.

Nov 20252 added

BMI Calculator

Calculate your Body Mass Index using height and weight — includes BMI category, healthy range, and what your score means.

Calorie Calculator

Find your daily calorie needs based on age, gender, weight, height, and activity level — for weight loss, maintenance, or gain.

Health Tools

Health & Fitness Calculators

Free calculators for BMI, daily calorie needs, ideal weight, pregnancy due dates, and more — with plain-language explanations of every result.

Body Composition & Weight

Understand your weight, body fat, and healthy ranges

Most Used

BMI Calculator

Calculate your Body Mass Index using height and weight — includes BMI category, healthy range, and what your score means.

Healthy weight checkBMI categoryAdult & child

Calorie Calculator

Find your daily calorie needs based on age, gender, weight, height, and activity level — for weight loss, maintenance, or gain.

Weight lossMuscle gainTDEE / BMR

Ideal Weight Calculator

Estimate your ideal weight range using four evidence-based formulas — Hamwi, Devine, Robinson, and Miller methods.

Healthy range4 formulas comparedBy height

Body Type Calculator

Identify your body shape — ectomorph, mesomorph, or endomorph — based on measurements, and understand what it means for fitness.

Ecto / Meso / EndoFitness tipsBody shape

Bra Size Calculator

Find your correct bra size using band and bust measurements — supports US, UK, EU, and international sizing standards.

US / UK / EU sizesBand + cup sizeInternational sizing

Reproductive Health

Pregnancy planning, due dates, and cycle tracking

Sensitive

Pregnancy Calculator

Calculate your estimated due date, current week of pregnancy, and key milestones — based on last menstrual period or conception date.

Due dateWeek by weekTrimester tracker

Sensitive

Ovulation Calculator

Estimate your ovulation date and fertile window based on your cycle length — helps with conception planning or cycle tracking.

Fertile windowConception planningCycle tracking

How these calculators work

Every tool uses established clinical and scientific formulas. Results include explanations so you understand what the numbers mean.

Evidence-based formulasBMI uses WHO standards. Calorie estimates use Mifflin-St Jeor. Ideal weight uses Devine, Robinson, Hamwi, and Miller methods.

Results in plain languageEvery calculation includes an explanation of what the number means — not just the result. No medical jargon without context.

For general information onlyThese tools are health screening aids, not medical devices. Always consult a qualified healthcare provider for diagnosis or treatment.

Free, private, no loginNo account required, no data stored, no usage limits. Calculations happen in your browser.