Online Calculators
18 free tools for health, fitness and everyday maths
18 toolsEvery ToolyLab calculator in one place: from percentages and body mass index to daily calories, macros, one-rep max, running pace, pregnancy and ovulation dates. Each tool answers one question clearly, and the formulas and sources are explained right below it.
Everything is calculated in your browser, so the weight, height or measurements you enter never reach a server. Health calculators are for general information only; talk to a professional before making medical decisions.
All tools in this category
Percentage Calculator
Calculate any percentage instantly
BMI Calculator
Check your Body Mass Index in seconds
Body Fat Calculator
US Navy method: body fat percentage from tape measurements
Ideal Weight Calculator
Find your ideal body weight for your height
Daily Calorie Calculator
Find your daily calorie needs (TDEE)
Calories Burned Calculator
How many calories an activity burns for your weight
BMR Calculator
Find your Basal Metabolic Rate
FFMI Calculator
Fat-Free Mass Index calculator for men and women
One Rep Max Calculator
Estimate your 1RM from a weight and reps
Running Pace Calculator
Pace per km and mile from your distance and time
Water Intake Calculator
How much water you should drink each day
Macro Calculator
Find your daily protein, carbs and fat
Pregnancy Calculator
Find your due date and pregnancy week
Ovulation Calculator
Find your ovulation day and fertile window
Period Calculator
Predict your next period and a 6-month cycle calendar
Lean Body Mass Calculator
Find your lean mass and lean percentage
Sleep Calculator
Ideal bedtimes and wake-up times based on 90-minute cycles
Dog & Cat Age Calculator
Your pet's age in human years, by breed size