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.
Try our free Intermittent Fasting Calculator for a custom fasting schedule and eating window. Supports 16:8, OMAD, 5:2, and more.
Get your personalized daily hydration plan with our free water intake calculator. Based on weight, activity, and climate factors.
Calculate your sleep debt by age with this free sleep debt calculator. Track weekly loss, see health risks, and get a recovery plan.
Use our free macro calculator online to get your personalized protein, carbs, and fat targets based on your goal and weight.
Calculate your daily nutrient needs with our free DRI calculator. Get personalized protein, carbs, fat, vitamins, and minerals based on age.
Use our free ultra processed food calculator to check ingredients, get your NOVA score, and find smart whole food swaps instantly.
Calculate daily iron requirement by age, gender, pregnancy, and diet. Free iron intake calculator with vegan adjustments. Instant results.
Convert blood glucose to A1C or fructosamine. Free A1C converter with ADA formulas. Get instant results and reference table.
Use our free Vitamin D Deficiency Calculator to assess your risk, check symptoms, and get your personalised IU dosage. Instant results based on clinical guidelines.
Create a customized diet plan based on your BMR, TDEE, and fitness goals. Lose, maintain, or gain weight with precision.
Free strength level calculator. Estimate your one rep max, compare to strength standards, and see your percentile rank. Perfect for powerlifters.
Use our free pro physique calculator to measure symmetry, proportions, and muscle potential. Get your physique score out of 100 now.
Use our free metabolic age calculator to discover your true body age and compare it to your real age with personalized improvement tips.
Use this Body Roundness Index calculator with waist and height. Free BRI score, risk meter, and visceral fat insights.
Calculate your DOTS powerlifting score with this free DOTS score calculator. Compare strength across body weights and genders. Instant results.
Calculate your Fat-Free Mass Index (FFMI) with this free FFMI calculator. Raw and normalized scores, muscularity tiers, and lean mass analysis.
Use our body fat percentage calculator to measure Navy Method, get your category, lean mass, and fat mass instantly.
Free GLP-1 protein requirement calculator for Ozempic, Wegovy, Mounjaro, and Zepbound users. Get daily protein targets to preserve muscle.
Use this calories calculator to estimate your daily energy needs based on age, weight, height, activity, and fitness goals for sustainable results.
Calculate your Body Mass Index using metric or imperial units. Understand what your BMI means for your overall health and wellness goals.
Stop the post-diet rebound. Use our free reverse dieting calculator to get a step-by-step weekly macro plan to safely increase your calories.
Use our free Cycling FTP Calculator to find your Functional Threshold Power, calculate all 7 training zones, and get your W/kg ratio instantly. No sign-up needed.
Use our free Creatine Loading Phase Calculator to find your exact daily loading and maintenance dose by bodyweight. Science-based, instant results. No sign-up needed.
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 to use. There are no hidden fees, no premium tiers, and no signup required. All 22 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.