Frequently Asked Questions
How accurate are these calculators?
Our calculators use science-backed formulas, but they provide estimates. Actual results vary based on training quality, nutrition, recovery, genetics, and measurement technique. Use them as guidelines, not absolutes. For the 1RM estimator, test with a 3–6 rep set for best accuracy.
What is a 1-rep max (1RM)?
Your 1-rep max is the heaviest weight you can lift for one complete repetition with proper form. It's used to assess strength and to program training intensity. You can test it directly or estimate it with the 1RM calculator (Brzycki, Epley, Lander).
What are macros and why do they matter?
Macros are macronutrients: protein, carbs, and fats. The TDEE & macro calculator breaks your daily calories into ratios based on your goal. Protein supports muscle, carbs fuel workouts, and fats support hormone production.
What's a good TDEE?
TDEE (Total Daily Energy Expenditure) is the calories your body burns daily. It depends on age, sex, weight, height, and activity. Our calculator uses the Mifflin-St Jeor equation. Eat below it to lose weight, above to gain, or at it to maintain.
What's the Steve Reeves formula for bicep size?
It estimates ideal arm size from wrist circumference, a marker of bone structure: ideal = wrist × 2.5, approximate natural ceiling = wrist × 2.8. Try it on the bicep size calculator.
What do the strength standards mean?
They rank your lifts: novice, intermediate, advanced, and elite, based on bodyweight multipliers. Check yours on the strength standards calculator.
Is my personal data stored?
No. All calculations happen locally in your browser. We don't store, transmit, or see any numbers you enter. We use Google AdSense for advertising, which may set cookies. See our Privacy Policy.
Can I use these calculators on my phone?
Yes. Everything is responsive and works on phones, tablets, and desktops — and works offline after the first load.
Should I consult a professional?
Yes. These calculators are educational tools. Before major changes to diet or training — especially with existing health conditions — consult a qualified fitness professional, registered dietitian, or physician. They provide estimates, not medical advice.