Health & Nutrition Calculators
These health and nutrition calculators turn everyday numbers, like a lab result, your height and weight, or your hours of sleep, into clear answers. Convert an A1C result, check your BMI, estimate your daily nutrient needs, or see how much sleep debt you have built up. Every calculator is free, needs no signup, and runs in your browser, so nothing you enter is stored. Results are educational estimates, not medical advice.
A1C Converter
Convert blood glucose to A1C or fructosamine. Free A1C converter with ADA formulas. Get instant results and reference table.
DRI Calculator
Calculate your daily nutrient needs with our free DRI calculator. Get personalized protein, carbs, fat, vitamins, and minerals based on age.
Sleep Debt Calculator
Calculate your sleep debt by age with this free sleep debt calculator. Track weekly loss, see health risks, and get a recovery plan.
Iron Intake Calculator
Calculate daily iron requirement by age, gender, pregnancy, and diet. Free iron intake calculator with vegan adjustments. Instant results.
Electrolyte Calculator
Use our free Electrolyte Calculator to find your daily sodium, potassium, magnesium, calcium & chloride needs. Personalised to your activity, climate & conditions.
Vitamin D Deficiency Calculator
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.
BMI Calculator
Calculate your Body Mass Index using metric or imperial units. Understand what your BMI means for your overall health and wellness goals.
GLP-1 protein calculator
Free GLP-1 protein requirement calculator for Ozempic, Wegovy, Mounjaro, and Zepbound users. Get daily protein targets to preserve muscle.
Which calculator should I use?
Pick the tool that matches what you have in hand:
- You have a lab result. Use the A1C Converter to see how blood glucose, A1C, and fructosamine relate.
- You want to know if your weight is in a healthy range. Use the BMI Calculator.
- You are checking a specific nutrient. Use the Vitamin D Deficiency Calculator, the Iron Intake Calculator, or the Electrolyte Calculator.
- You want a broader picture of daily nutrient needs. Use the DRI Calculator.
- You are not sleeping enough. Use the Sleep Debt Calculator.
- You take GLP-1 medication and want to protect your protein intake. Use the GLP-1 Protein Requirement Calculator, and talk to your prescriber about your plan.
How these calculators work
Each calculator uses published formulas, not guesses. The A1C Converter applies the equation from the A1C-Derived Average Glucose study, and BMI divides your weight by your height squared. Nutrient calculators estimate daily needs from factors such as age and sex, and the Sleep Debt Calculator compares the hours you slept with the recommended range for your age group.
These are estimates. Individual needs vary with health conditions, medications, pregnancy, and other factors a calculator cannot see.
Frequently Asked Questions
Are online health calculators accurate?
They are as accurate as the formulas and inputs behind them. A calculator gives a reasonable estimate for the average person, but individual results vary, and a lab test or a clinician’s assessment is more precise. Use the result as a starting point, not a verdict.
Can a calculator diagnose a vitamin D or iron deficiency?
No. A calculator can show that you may be at risk, but confirming a deficiency takes a blood test ordered by a healthcare professional. If a result worries you, talk to your doctor about testing.
Which health calculator should I use first?
Start with the one that matches what you have in hand. If you have a lab report, use the A1C Converter. If you want to check your weight range, use the BMI Calculator. For a broader picture of daily nutrient needs, start with the DRI Calculator.
Are these calculators free, and do I need to sign up?
Yes, they are free, and no signup or email address is needed.
Is my data stored?
No. Calculations run in your browser, and nothing you enter is sent to a server or saved.
Sources
- Nathan DM, et al. Translating the A1C Assay into Estimated Average Glucose Values. Diabetes Care. 2008;31(8):1473-1478.
- Hirshkowitz M, et al. National Sleep Foundation’s sleep time duration recommendations: methodology and results summary. Sleep Health. 2015;1(1):40-43.
- Centers for Disease Control and Prevention. About Adult BMI.
Medical disclaimer
These calculators provide educational estimates and are not medical advice. They cannot diagnose, treat, or manage any condition. Talk to a doctor or registered dietitian before changing your diet, supplements, or medication, especially if you are pregnant, breastfeeding, or have a medical condition.
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