Health & Fitness Calculators
Tools to track your calories, sleep cycles, BMI, and overall wellness goals.
Free health calculators for BMI, calorie needs, BAC estimation, sleep cycles, and pregnancy planning. All tools run in your browser — your health data stays on your device.
Why Use Free Health & Fitness?
- → Get a reliable calorie and BMR baseline using the Mifflin-St Jeor formula before starting any diet — guessing leads to either starvation or no results.
- → Estimate your one-rep max safely from sub-max sets instead of testing to failure and risking injury.
- → Your weight, body measurements, and health data are never uploaded — every calculation runs entirely in your browser.
How to choose the right tool
Start with the result you need, then choose the smallest tool that answers that question directly. If you are estimating, forecasting, or comparing options, use the calculator that matches the decision rather than a general spreadsheet. For example, a quick fee estimate belongs in a fee calculator, while a longer planning question belongs in a budgeting, ROI, or comparison tool. This keeps the inputs focused and makes the result easier to check.
What makes these tools private
The tools in this category are designed to run in your browser whenever possible. That means your numbers, text, files, or planning details stay on your device instead of being uploaded to an account dashboard. You can refresh the page, change the inputs, and compare scenarios without creating a login or storing personal work in our database.
A simple workflow
Use one tool for the first pass, copy the result you care about, then open a related tool if the decision needs more detail. Most people get the best answer by moving from a quick estimate to a more specific calculator, not by trying to force every question into one oversized form. Each page includes plain-language notes so you can understand the formula, common mistakes, and when the answer should be treated as an estimate instead of professional advice.
Before you rely on the result
Double-check the assumptions behind any calculator result before you use it for money, health, taxes, travel, legal, or work decisions. Small input changes can shift an estimate quickly, especially when rates, deadlines, file formats, or platform rules are involved. When a page includes a formula, source note, or last-updated date, use that context to decide whether the result is current enough for your situation.
If a result looks surprising, run the numbers again with simpler inputs and compare the answer against another trusted source before acting on it.
Calorie Calculator
Calculate exactly how many calories you need daily.
Calorie Deficit
Calculate your TDEE and daily calorie target.
BMI Calculator
Check your Body Mass Index score and category.
1RM Calculator
Calculate your one-rep max and get weight tables.
Bench Press Calc
Estimate your bench press max safely.
Sleep Cycle
Optimize bedtime based on 90-minute REM cycles.
BAC Estimator
Estimate blood alcohol levels based on biological factors.
Pregnancy Due Date
Calculate your baby's arrival date and track pregnancy weeks.
Deadlift Calculator
Calculate your one-rep max deadlift from sub-max sets.
One Rep Max Calculator
Estimate your true 1RM across all barbell lifts.
Squat Max Calculator
Find your one-rep max squat from any sub-max set.
Frequently Asked Questions
What health calculators are available?
BMI calculator, calorie calculator (Mifflin-St Jeor), BAC calculator, sleep cycle calculator, calorie deficit calculator, pregnancy due date calculator, and pet age calculator.
Are these tools medically accurate?
They use validated formulas (Mifflin-St Jeor for calories, standard BAC formulas) but provide population-average estimates. They are not substitutes for medical advice.
Is my health data private?
Yes. Every calculation runs locally in your browser. Your age, weight, height, and other health inputs are never sent to a server.
Should I use these tools for medical decisions?
No — use them for general wellness awareness and planning. Always consult a licensed healthcare provider for medical decisions.