30+ free tools • Science-based formulas • No data stored • Works on any device
DietPlanner.io gives you instant, science-based health and fitness calculators, completely free, with no account needed. Whether you want to check your BMI, calculate a calorie deficit, plan your macros, find your intermittent fasting window, or track your sleep debt, every tool runs privately in your browser and delivers results in seconds. No app to download. No data collected.
Convert an A1C result, check your BMI, assess vitamin D deficiency risk, and estimate iron, electrolyte, and daily nutrient needs. Track your sleep debt too.
Work out your daily calories and macros, plan carb cycling or intermittent fasting, build a weight loss plan, and set a reverse diet.
Estimate body fat percentage, body roundness (BRI), fat-free mass index (FFMI), metabolic age, and body type to track real progress.
Estimate your one-rep max and DOTS score, plan creatine loading, find your cycling FTP, and calculate calories burned rucking or on the StairMaster.
Use our free pro physique calculator to measure symmetry, proportions, and muscle potential. Get your physique score out of 100 now.
Try our free Intermittent Fasting Calculator for a custom fasting schedule and eating window. Supports 16:8, OMAD, 5:2, and more.
Convert blood glucose to A1C or fructosamine. Free A1C converter with ADA formulas. Get instant results and reference table.
Free strength level calculator. Estimate your one rep max, compare to strength standards, and see your percentile rank. Perfect for powerlifters.
Use our StairMaster Calories Burned Calculator to estimate calories using your weight, duration, and workout intensity.
Create a customized diet plan based on your BMR, TDEE, and fitness goals. Lose, maintain, or gain weight with precision.
Every calculator on DietPlanner.io is built on established clinical and scientific formulas. The calorie calculator uses the Mifflin-St Jeor equation, the gold standard for estimating resting metabolic rate. The body fat percentage tool applies the U.S. Navy circumference method. The A1C converter uses ADA-validated formulas. The DOTS score calculator uses coefficients from official powerlifting federation data. All calculations happen entirely in your browser. No information is sent to our servers. No account is created. No data is stored or shared. You get accurate, private results, instantly.
Yes, every calculator on this site is completely free, with no hidden fees, no premium tiers, and no signup required. All 30+ tools are available to everyone instantly.
No account is needed. Every tool works immediately without registration. You do not need to provide an email address or any personal information.
Yes. All calculations happen in your browser. No data is sent to our servers, stored in a database, or shared with third parties. Your inputs are completely private.
Our tools use the same clinical formulas referenced by doctors and dietitians including the Mifflin-St Jeor equation for calories, the Navy Method for body fat, and ADA-validated formulas for A1C. Results are as accurate as any tool you would find on a medical or fitness website.
If your goal is weight loss, start with the BMI Calculator and then the Calories Calculator to find your daily target. If you want to track nutrition, go to the Macro Calculator. For general health, the Sleep Debt Calculator and Water Intake Calculator are great starting points.