About FitCalc

Getting into fitness should not start with a paywall. You want to know your TDEE so you can plan your meals. You want to figure out your training heart rate zones so you can run smarter. You want to see how different macro splits look at your calorie target. These are basic questions, and the answers should be free and instant.

That is why FitCalc exists. We built 12 health and fitness calculators that give you actionable numbers in seconds. BMI, TDEE, calorie deficit targets, macronutrient breakdowns, body fat estimates, one-rep max projections, running pace calculations, heart rate zone mapping, hydration targets, ideal weight ranges, pregnancy due dates, and sleep cycle timing. All free. All running in your browser. No app to download, no account to create, no credit card to enter.

Who FitCalc Is For

FitCalc is for the runner who just wants to know what pace to hold for a sub-2-hour half marathon. It is for the lifter trying to estimate a one-rep max without actually maxing out. It is for someone starting a diet who needs a sane calorie target based on their activity level, not some one-size-fits-all number from a magazine.

It is also for the expecting parent who wants a quick due date estimate, or the person who keeps waking up groggy and wonders if their alarm is set at the wrong point in a sleep cycle. These are the everyday questions that led us to build each tool.

Your Body, Your Data

Health data is deeply personal. Your weight, your body fat percentage, your calorie intake -- that is nobody's business but yours. FitCalc is a static website. Every calculation happens in your browser, on your device. We have no server receiving your measurements. We have no database storing your stats. We literally cannot see what you enter.

We made that choice deliberately. You should be able to check your BMI without worrying about where that number ends up. You should be able to calculate a calorie target without giving a company your email address first.

A Starting Point, Not a Prescription

We want to be upfront: FitCalc gives you estimates based on well-known formulas. It is not a replacement for working with a doctor, dietitian, or personal trainer. Bodies are complicated. Formulas are simplified models. Use our numbers as a starting point, then adjust based on your real-world results and professional guidance.

Got a suggestion for a tool we should build? Spot something that does not look right? We are always listening -- reach us at [email protected].