Is this calculator free to use?

Yes, completely free. No sign-up, no ads, no downloads. Everything runs in your browser.

What formula does the BMR calculator use?

The BMR calculator uses the Mifflin-St Jeor equation, considered the most accurate standard formula. Results are shown for five activity levels.

How accurate are the currency exchange rates?

Rates are fetched live from open.er-api.com with ECB rates as fallback. Bitcoin and Ethereum prices come from the Coinbase API and are updated daily.

How is body fat percentage calculated?

Body fat is calculated using the US Navy Method, which uses height, neck, waist, and hip measurements to estimate body fat percentage accurately without special equipment.

Free Online Calculator — Scientific, Unit Converter, BMI, Body Fat, Calories & More

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Free Online Scientific Calculator

A fast, mobile-friendly calculator with Basic and Scientific modes. Supports arithmetic, trigonometry (sin, cos, tan and inverses), logarithms, powers, roots, factorial, π, and Euler's number. Switch between Degrees and Radians for trig functions. Full keyboard support on desktop — press Enter to calculate, Backspace to delete, Escape to clear.

How do I use the Scientific mode? ▼

Tap Sci in the top-right corner to reveal 20 extra functions including trig, inverse trig, log, ln, powers, roots, π, e, factorial, and absolute value. Use the DEG/RAD toggle for angle units.

Does it support keyboard input? ▼

Yes. On desktop use number keys, +−×÷ operators, Enter to calculate, Backspace to delete, and Escape to clear. Parentheses ( ) are also supported.

What does the live preview do? ▼

As you type an expression, the result is shown in small text below the main display in real time — so you can verify the answer before pressing equals.

From

1000

Length & Distance Converter

Convert between 10 units of length and distance including metric (meters, kilometers, centimeters, millimeters), imperial (miles, yards, feet, inches), nautical miles, and even light years. Instant conversion as you type.

How many feet are in a meter? ▼

1 meter = 3.28084 feet. Select Meter → Foot and enter 1 to confirm instantly.

How do I convert miles to kilometers? ▼

Select Mile (mi) in the From field and Kilometer (km) in the To field. 1 mile = 1.60934 km. Enter any value for an instant result.

From

Temperature Converter

Convert between Celsius, Fahrenheit, Kelvin, and Rankine instantly. Useful for cooking, science, weather, and engineering. The converter handles all non-linear formulas (like °F = °C × 9/5 + 32) automatically.

How do I convert Celsius to Fahrenheit? ▼

Select Celsius → Fahrenheit and type your temperature. The formula is °F = (°C × 9/5) + 32. For example, 100°C = 212°F (boiling point of water).

What is absolute zero in Celsius? ▼

Absolute zero is 0 Kelvin = −273.15°C = −459.67°F. Enter 0 in Kelvin and convert to see the equivalents.

From

1000

Weight & Mass Converter

Convert between kilograms, grams, milligrams, pounds, ounces, metric tons, stone, and carats. Covers everyday needs like cooking and body weight as well as scientific and jewellery use cases.

How many pounds in a kilogram? ▼

1 kilogram = 2.20462 pounds. Select Kilogram → Pound and enter 1 to verify instantly.

What is a stone in kg? ▼

1 stone = 6.35029 kg. Commonly used in the UK and Ireland for body weight. Select Stone → Kilogram to convert.

From

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Fetching live rates…

Live Currency Converter with BDT & Crypto

Converts between 17 fiat currencies including Bangladeshi Taka (BDT), US Dollar, Euro, British Pound, Indian Rupee, UAE Dirham, Saudi Riyal, and more — plus Bitcoin (BTC) and Ethereum (ETH). Rates are fetched live from open.er-api.com with ECB rates as a fallback. Crypto prices come from Coinbase API.

How current are the exchange rates? ▼

Rates are fetched live on page load from open.er-api.com, updated daily. A timestamp is shown below the converter. If that fails, ECB rates are used as fallback.

Where do crypto prices come from? ▼

Bitcoin and Ethereum spot prices are fetched in real time from the Coinbase public API, so they reflect the current market price when the page loads.

Is BDT (Bangladeshi Taka) supported? ▼

Yes. BDT is fully supported and is set as the default "To" currency. It is sourced from open.er-api.com which includes BDT in its live feed.

From

Area Converter

Convert square meters, square kilometers, square feet, square inches, square miles, acres, and hectares. Useful for real estate, land measurement, agriculture, and construction projects.

How many square feet in an acre? ▼

1 acre = 43,560 square feet. Select Acre → ft² and enter 1 to see the exact conversion.

What is a hectare in square meters? ▼

1 hectare = 10,000 square meters. It is the standard unit for measuring large areas of land in agriculture and forestry.

From

Speed Converter

Convert between m/s, km/h, mph, knots, Mach number, and the speed of light. Covers everyday use (driving, running), aviation, marine navigation, and physics problems.

How fast is Mach 1 in km/h? ▼

Mach 1 = 1235.22 km/h (343 m/s at sea level, 20°C). Select Mach → km/h and enter 1 to see the result.

What is a knot in mph? ▼

1 knot = 1.15078 mph or 1.852 km/h. Knots are the standard speed unit in aviation and maritime navigation.

Body Mass Index (BMI)

Unit

Heightcm

Weightkg

Your BMI

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Under <18.5 Normal 18.5–25 Obese >30

BMI Calculator — Body Mass Index

BMI (Body Mass Index) is calculated by dividing your weight (kg) by the square of your height (m²). It classifies weight status as Underweight (<18.5), Normal weight (18.5–24.9), Overweight (25–29.9), or Obese (≥30). Supports both metric and imperial units.

What is a healthy BMI range? ▼

A BMI between 18.5 and 24.9 is considered healthy for most adults. Below 18.5 is underweight, 25–29.9 is overweight, and 30+ is classified as obese. BMI is a screening tool, not a diagnostic measure.

Is BMI accurate for everyone? ▼

BMI doesn't account for muscle mass, bone density, or fat distribution. Athletes may show a high BMI despite being healthy. It's best used alongside other health indicators like waist circumference and body fat percentage.

Basal Metabolic Rate (BMR)

Unit

Sex

Ageyrs

Heightcm

Weightkg

Basal Metabolic Rate

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kcal/day

By activity level

BMR Calculator — Basal Metabolic Rate

Your BMR is the number of calories your body burns at complete rest to maintain basic functions. This calculator uses the Mifflin-St Jeor equation — the most accurate standard formula — and shows your daily calorie needs across five activity levels from sedentary to extra active.

What is the Mifflin-St Jeor formula? ▼

Men: BMR = 10W + 6.25H − 5A + 5. Women: BMR = 10W + 6.25H − 5A − 161. Where W = weight in kg, H = height in cm, A = age in years. Introduced in 1990, it is more accurate than the older Harris-Benedict equation.

How do I use BMR to lose weight? ▼

Multiply your BMR by your activity factor to get TDEE (total daily energy expenditure). Eating 500 kcal below TDEE daily creates a deficit of ~0.5 kg/week. Use the Calories tab for a full breakdown.

Daily Calorie Needs (TDEE)

Unit

Sex

Ageyrs

Heightcm

Weightkg

Activity Level

Goal

Daily Target

—

kcal/day

Calorie Calculator — TDEE & Weight Goals

Calculates your Total Daily Energy Expenditure (TDEE) using the Mifflin-St Jeor equation, then adjusts for your weight goal. A deficit of 500 kcal/day ≈ 0.5 kg loss per week. A surplus of 500 kcal/day ≈ 0.5 kg gain per week. The minimum floor is 1,200 kcal/day for safety.

What is TDEE? ▼

TDEE (Total Daily Energy Expenditure) is the total calories you burn per day including exercise and daily movement. It equals your BMR multiplied by an activity factor ranging from 1.2 (sedentary) to 1.9 (extra active).

How many calories to lose 1 kg per week? ▼

1 kg of fat ≈ 7,700 calories. To lose 1 kg/week you need a daily deficit of approximately 1,100 kcal. This is aggressive — losing 0.5 kg/week (−500 kcal/day) is generally more sustainable and healthier.

Body Fat % — US Navy Method

Unit

Sex

Heightcm

Neckcm

Waistcm

Body Fat Percentage

—

Body Fat % Calculator — US Navy Method

Uses the US Navy circumference method to estimate body fat percentage without expensive equipment. For men, measures height, neck, and waist. For women, also adds hip measurement. Results are classified using American Council on Exercise (ACE) categories: Essential Fat, Athlete, Fitness, Average, and Obese.

How accurate is the US Navy method? ▼

The US Navy method has an accuracy of ±3–4% compared to DEXA scans. It's one of the most practical field methods and is used by the US military for fitness assessments. Measure at the widest point for best results.

What is a healthy body fat percentage? ▼

For men: 6–17% is Athletic/Fitness, 18–24% is Average. For women: 14–24% is Athletic/Fitness, 25–31% is Average. Essential fat (minimum for survival) is 2–5% for men and 10–13% for women.

Where exactly should I measure waist and neck? ▼

Neck: measure at the narrowest point, just below the larynx (Adam's apple). Waist for men: measure at the navel level. Waist for women and hip: measure at the widest point. Keep the tape horizontal and snug but not tight.

Ideal Body Weight

Unit

Sex

Heightcm

Healthy BMI Range

—

Formula Estimates

Ideal Weight Calculator — 4 Formulas

Shows ideal body weight based on four clinically established formulas: Robinson (1983), Miller (1983), Devine (1974), and Hamwi (1964), plus a healthy BMI range based on your height. These formulas were developed for medical dosing and weight classification, not purely for appearance.

Which ideal weight formula is most accurate? ▼

No single formula is universally most accurate — they typically agree within 5–10%. The Healthy BMI range (18.5–24.9) is the most widely used modern standard. The Robinson formula is generally preferred for clinical use today.

Should I aim for the ideal weight number exactly? ▼

These are estimates, not targets. Body composition (muscle vs fat), bone density, and individual health matter more than a specific number. The healthy BMI range gives a practical window to aim for rather than a single ideal number.

Macro Calculator

Unit

Sex

Ageyrs

Heightcm

Weightkg

Activity

Goal

Daily Calories

—

kcal/day

Macro Targets

Macro Calculator — Protein, Carbs & Fat

Calculates your optimal daily protein, carbohydrate, and fat targets based on TDEE and your goal. Cut: 80% of TDEE, 35/35/30 split. Maintain: 100% of TDEE, 30/40/30 split. Bulk: 110% of TDEE, 30/45/25 split. Protein and carbs provide 4 kcal/g; fat provides 9 kcal/g.

How much protein do I need per day? ▼

General guidance is 1.6–2.2 g of protein per kg of body weight for people who train regularly. This calculator targets 35% of calories from protein when cutting (roughly 1.8–2g/kg for most people).

What is the difference between Cut, Maintain, and Bulk? ▼

Cut: eat at a 20% calorie deficit to lose fat while preserving muscle. Maintain: eat at TDEE to keep weight stable. Bulk: eat at a 10% surplus to build muscle with minimal fat gain (lean bulk).

Should I track macros or just calories? ▼

For general weight loss, calorie tracking alone is effective. For body recomposition (losing fat while building muscle), tracking macros — especially protein — gives better results. Start with calories if you're new to tracking.

Free Online Scientific Calculator

Length Converter

Temperature Converter

Weight Converter

Live Currency Converter

Area Converter

Speed Converter

BMI Calculator

BMR Calculator

Calorie and TDEE Calculator

Body Fat Percentage Calculator

Ideal Weight Calculator

Macro Calculator