FFitCalc
8+ science-backed calculators

Everything you need to calculate your fitness journey.

Free, accurate fitness calculators with clear explanations, charts and actionable tips — not just a number.

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Yes — every calculator is completely free to use, with no sign-up required. We show clear explanations and science-backed formulas alongside every result.

We use peer-reviewed formulas (like Mifflin–St Jeor for metabolism) and cite our sources. Predictive equations are estimates — use them as a starting point and refine with your own data.

Yes. Every relevant calculator lets you switch between metric (kg, cm) and imperial (lb, in) with a single tap.

No. All calculations run instantly in your browser — nothing you enter is sent to a server or saved.

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