Free tools
Free fitness and nutrition calculators
14 free calculators, each built on published formulas and official guidance, with the working shown and the sources linked. They run in your browser: nothing you type is sent anywhere.
Food and calories
Calorie deficit calculator
Estimate your BMR and maintenance calories (TDEE) with the Mifflin–St Jeor equation, then daily targets to lose 0.25–0.75 kg a week within safe limits.
Indian food calorie counter
Add up calories, protein, carbs and fat for Indian meals: roti, paratha, idli, dosa, sambar, dal, rice, paneer and 37 more foods, in real portions.
Protein calculator
Calculate a general daily protein range in kg or lb. See separate exercise and weight-loss research contexts, assumptions and a worked serving example.
Water intake calculator
Find a daily water target from European (EFSA) and US National Academies guidance, with your own sweat rate for exercise, pregnancy and breastfeeding.
Body measurements
BMI calculator
Work out your BMI with both WHO and Asian/Indian cut-offs (ICMR-NIN 2024), and add your waist to see your waist-to-height ratio, a better guide to belly fat.
Body fat calculator
Estimate your body fat percentage from a tape measure with the US Navy method, see its real error against DXA scans and the healthy range for your age and sex.
Strength training
One-rep max calculator
Estimate your one-rep max from the weight and reps you lifted, with seven published formulas, reps in reserve and a training-load table. In kg or lb.
RPE calculator
Turn a set at an RPE into an estimated 1RM, then find the load for any reps and RPE. With a full RPE chart based on reps in reserve. Free, kg or lb.
Plate calculator
Enter a target weight to see which plates go on each side of the bar, in kg or lb, with a 20 kg, 15 kg or 45 lb bar and optional collars. Free.
Cardio and activity
Heart rate zone calculator
Estimate your maximum heart rate from age, then get five training zones, zone 2 and target heart rate ranges, by % of max or heart-rate reserve (Karvonen).
VO2 max calculator
Estimate VO2 max three ways: resting and maximum heart rate, Cooper’s 12-minute run or the Rockport one-mile walk, and see how it compares by age and sex.
Steps to calories calculator
Convert steps into calories burned, distance and walking time from your weight, height and pace. Shows the calories from walking itself, not just the total.
Sleep and recovery
Caffeine calculator
Add your coffee, tea or energy drinks to see how much caffeine is still in your body at bedtime, the half-life curve, and the latest time to have caffeine.
Sleep calculator
Pick a wake-up time to see bedtimes for 7 to 9 hours of sleep, or a bedtime to see when to wake. With what research says about sleep cycles and regularity.
How we build the tools
- Published methods only. Every formula comes from a peer-reviewed paper or an official body, such as EFSA, the US National Academies, the WHO, NICE or ICMR-NIN, cited on the tool’s page.
- The working is shown. Each page explains the calculation and its limits, so you can judge the number instead of trusting a black box.
- Private by design. The tools calculate in your browser. Inputs have no form names, nothing is submitted, and nothing is stored.
- Not medical advice. The tools give general estimates for healthy adults. They don’t diagnose anything or replace advice from a professional who knows your situation.
The research behind many of these tools is explained, chart by chart, in the Bodyvault research library. To keep your own numbers over time, with your data on your phone, try the Bodyvault app.
Questions
Are these calculators free?
Yes. They are free to use, with no sign-up and no limit.
Do the calculators store my data?
No. They run in your browser and send nothing to a server.
How accurate are the estimates?
Each page states the method’s known accuracy. Formulas describe averages, so treat results as starting points and check them against your own records.