What health calculators does Texterfly offer?

Texterfly offers 3 free health calculators: a BMI Calculator (adult and child/teen modes, visual gauge, healthy weight range), a Calorie & Macro Calculator (Mifflin-St Jeor and Katch-McArdle formulas, macronutrient breakdown, goal-based timeline), and a Pregnancy Due Date Calculator (last menstrual period or conception date methods, trimester guide, weekly development milestones). All are for informational purposes only.

What do the BMI categories mean?

BMI (Body Mass Index) categories for adults are: Underweight (below 18.5), Normal weight (18.5–24.9), Overweight (25–29.9), Obese Class I (30–34.9), Obese Class II (35–39.9), and Obese Class III (40 and above). Note that BMI has significant limitations — it does not account for muscle mass, bone density, age, sex, or ethnicity. Athletes may have a high BMI due to muscle, not fat. Always consult a healthcare professional for a full health assessment.

What is the Mifflin-St Jeor formula?

The Mifflin-St Jeor formula estimates Basal Metabolic Rate (BMR) — calories burned at rest. For men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5. For women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161. Multiplying BMR by an activity factor gives TDEE (Total Daily Energy Expenditure), which is the estimated number of calories needed to maintain current weight.

TDEE (Total Daily Energy Expenditure) is the estimated total number of calories you burn per day, including physical activity. It is calculated by multiplying your BMR (Basal Metabolic Rate) by an activity factor: Sedentary (×1.2), Lightly active (×1.375), Moderately active (×1.55), Very active (×1.725), Extra active (×1.9). To lose weight, eat fewer calories than your TDEE; to gain, eat more.

How is a pregnancy due date calculated?

The most common method is Naegele's rule: add 280 days (40 weeks) to the first day of your Last Menstrual Period (LMP). For example, if your LMP was January 1, the estimated due date is October 8. Alternatively, add 266 days to a known conception date. Only about 5% of babies are born on their exact due date — it's an estimate within a 2-week window.

What are the pregnancy trimesters?

First Trimester: Weeks 1–12 (months 1–3). Key developments: fertilisation, heart formation, organ development. Second Trimester: Weeks 13–26 (months 4–6). Key developments: movement felt, sex identifiable, rapid growth. Third Trimester: Weeks 27–40+ (months 7–9+). Key developments: lungs mature, weight gain, preparation for birth.

Are these calculators a substitute for medical advice?

No. These calculators are for informational and educational purposes only. They are not designed to diagnose, treat, cure, or prevent any medical condition. BMI, calorie needs, and pregnancy timelines are estimates based on statistical formulas — individual health varies significantly. Always consult a qualified healthcare professional, doctor, or registered dietitian for personalised medical guidance.

How accurate is the BMI calculator?

The BMI formula is mathematically accurate — it correctly calculates weight (kg) divided by height (m²). However, BMI as a health metric has well-documented limitations: it does not distinguish between fat and muscle, does not account for where fat is stored (visceral vs subcutaneous), and may misclassify athletes as overweight and elderly people with muscle loss as normal weight. Use BMI as one data point, not a definitive measure of health.

Are these health calculators free?

Yes. All 3 health calculators are 100% free with no registration, subscription, or payment required.

Is my health data private?

Yes. All calculations run entirely in your browser. Your weight, height, age, activity level, and other personal health data are never sent to any server or stored anywhere.

A MET, or Metabolic Equivalent of Task, is a unit of energy expenditure. One MET is roughly the energy used sitting quietly, and an activity rated 8 METs uses about eight times that.

Back to Health & Fitness Calculators

Calories Burned Calculator

Estimate calories burned for 40+ activities using standard MET values. Compare activities and track a daily total. Free, no sign-up.

That's calories out — what about calories in?

Find your daily calorie target with our Calorie Calculator

Calorie Calculator

Your Workout

Activity

MET value: 9.8

Duration (minutes)

Body Weight

Net calories onlyExcludes the calories you'd burn at rest anyway (subtracts 1 MET).

Estimated Calories Burned

368 kcal

Running, 6 mph (10 min/mile) · 30 min · about 735 kcal/hour

That's Roughly…

🍌

3.5

medium bananas

🥤

2.6

cans of soda (12 oz)

🍕

1.3

slices of pizza

🍩

1.5

glazed donuts

Compare Every Activity

Calories burned in 30 minutes at your weight, highest to lowest.

MET-based estimates are averages — your actual burn varies with fitness level, body composition, age, terrain, and effort. Treat the number as a reasonable estimate, not an exact measurement. This tool is for general reference only, not medical advice.

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Free Calories Burned Calculator — 40+ Activities, MET-Based

Pick an activity, enter how long you did it and your body weight, and get an instant estimate of the calories you burned — using standard MET (Metabolic Equivalent of Task) values from the Compendium of Physical Activities. Choose from over 40 activities across walking, running, cycling, swimming, the gym, sports, and everyday chores, add several to a running daily total, or compare every activity side by side at your weight. It's the "calories out" half of the equation — pair it with our Calorie Calculator to see your daily "calories in" target too. Everything runs instantly in plain JavaScript, no sign-up required.

The MET Formula Explained

One MET is the energy you spend sitting quietly at rest. Every activity is assigned a multiple of that: walking briskly is about 5 METs, meaning it burns roughly five times the energy of sitting still. The calories burned are then calculated as MET × body weight in kilograms × duration in hours. A 75 kg person running at 6 mph (9.8 METs) for 30 minutes burns about 9.8 × 75 × 0.5 ≈ 368 calories. The "Net calories only" option subtracts 1 MET from the activity's value so the result shows only the extra calories beyond what your body would have burned at rest anyway.

⚖️ Heavier = more calories

Moving more body mass takes more energy, so the same workout burns more calories for a heavier person than a lighter one.

🧮 Gross vs. net

Gross includes your resting burn during the workout; net counts only the extra. Fitness trackers usually report gross, so it's the default here.

Getting the Most Out of Your Estimate

📊

Use the comparison chart to pick your workout

The chart ranks every activity by calories burned in your chosen time at your weight — handy if you have 30 minutes and want to know which option gives the most for the time.

➕

Build a daily total

Add each session to Today's Workout Total to see the combined burn from a morning run plus an evening lift, without doing the math yourself.

🎯

Match the intensity honestly

Pick the speed or effort level that matches how hard you actually worked — "moderate" and "vigorous" versions of the same activity can differ by several METs.

⌚

Expect differences from your tracker

Wearables use heart rate and personal data, so their numbers will differ from a MET estimate. Neither is exact — use whichever you'll track consistently over time.

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Don't over-credit exercise at the table

It's easy to overestimate a workout and undercount food. Pairing a burn estimate with a calorie target keeps the whole picture honest.

Frequently Asked Questions

How are calories burned calculated?

Using the MET formula: calories = MET value × body weight in kilograms × duration in hours. Each activity has a published MET value reflecting how much energy it takes compared to resting.

What is a MET?

A MET (Metabolic Equivalent of Task) is a unit of energy expenditure. One MET is roughly the energy you use sitting quietly; an activity rated 8 METs uses about eight times that.

Why does my fitness tracker give a different number?

Trackers estimate from heart rate, movement, and personal data, while this calculator uses a standard average MET value for the activity. Both are estimates, so small-to-moderate differences are normal.

What does "net calories only" mean?

Net calories exclude the energy your body would have burned at rest during that same time. It's calculated by subtracting 1 MET from the activity's value, and shows only the extra calories the activity itself added.

Does age or gender affect the result?

This standard MET method uses only weight and duration, so it doesn't adjust for age, sex, or fitness level. Real-world burn can be a bit higher or lower depending on those factors.

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