Frequently Asked Questions

Is FitCalCalc really free, and do I need to create an account?

Yes. Every calculator on FitCalCalc is 100% free and requires no sign-up, email, or payment. All calculations run locally in your browser, so you can use the tools indefinitely without registering for anything.

Does FitCalCalc work offline?

Because the math is performed entirely in your browser, the calculators keep working even if your internet connection drops. Only fonts, stylesheets, and ad scripts need a network; the core calculations do not.

What is TDEE and how does the calculator estimate it?

TDEE (Total Daily Energy Expenditure) is the total calories you burn in a day. FitCalCalc first estimates your BMR with the Mifflin-St Jeor equation, then multiplies it by an activity factor you choose, and optionally adds calories burned from exercise tracked via the MET Activity tool. Activity factors follow public-health guidance such as the ACSM standards.

Which BMR formula does FitCalCalc use?

By default we use the Mifflin-St Jeor equation, which research shows is the most accurate for the general population. The site also compares seven formulas side by side so you can see how results differ across methods.

How accurate are the results?

The equations are scientifically established and useful for planning, but they are estimates. Real metabolism varies with genetics, body composition, and health. Treat the output as a starting point and adjust based on real-world progress over several weeks. For training-intensity context, see the American College of Sports Medicine activity guidelines.

Is BMI a reliable measure of health?

BMI is a quick screening tool based only on height and weight. It does not distinguish muscle from fat, so athletes can read "overweight" despite low body fat. Use it alongside the Body Fat % and Measurements tools for a fuller picture. The CDC likewise frames BMI as a screening tool, not a diagnostic measure.

How does the Body Fat % estimate work?

We use the U.S. Navy circumference method, which combines height, waist, hip, and neck measurements. It is a practical field estimate, not a medical measurement like DEXA, but it tracks changes well when measured consistently.

What is 1RM and why should I care?

1RM (one-rep max) is the most weight you can lift for a single repetition. Knowing it lets you set safe, effective loads for strength and hypertrophy training. The calculator estimates it from a lighter weight and the reps you completed.

What does the MET Activity tracker do?

MET (Metabolic Equivalent of Task) values express how intense an activity is versus rest. Enter your activities and duration and the tool estimates the extra calories burned, which you can fold into your daily TDEE for tighter targets.

What is Reverse TDEE?

Reverse TDEE works backward from your actual food intake and weight trend to reveal how many calories you truly burn. It is useful when the formula estimate feels off, or after a diet when your metabolism has adapted.

How is the Water Intake recommendation calculated?

We base the estimate on body weight and activity level, then add extra for hot climates or intense training. It is a general hydration guideline; thirst and urine color remain the best day-to-day signals.

Are my personal details and calculations private?

Yes. FitCalCalc stores nothing on a server and sends no input data anywhere. Everything you type stays in your browser. See our Privacy Policy for the full details on what (and what isn't) collected.

Are there special adjustments for female users?

The BMR equations already differ by biological sex. In addition, the calorie and macro tools let you account for menstrual-cycle phases and note that hormonal changes can shift hunger and water retention across the month.

Can I print or save my results?

Yes. Each calculator has a print button that opens a clean, ink-friendly layout. You can save it as a PDF from your browser's print dialog to keep a record of your plan.