One-Rep Max Calculator — Your one-rep max (1RM) is the heaviest weight you can lift for a single rep with good form. You rarely actually test it — going to true failure is fatiguing and risky. Instead, you do a set of 3-8 reps at a submaximal weight and use a formula to estimate what you could have done for 1 rep.
All math runs locally. No data leaves your browser.
Estimates come from predictive formulas, not actual lifts — treat them as guidance, not medical or training advice. Testing a true one-rep-max carries injury risk; use a spotter and progress gradually.
Was One-Rep Max Calculator useful?
ما هو One-Rep Max Calculator؟
Your one-rep max (1RM) is the heaviest weight you can lift for a single rep with good form. You rarely actually test it — going to true failure is fatiguing and risky. Instead, you do a set of 3-8 reps at a submaximal weight and use a formula to estimate what you could have done for 1 rep.
The two most common formulas are Epley (1RM = weight × (1 + reps/30)) and Brzycki (1RM = weight × 36 / (37 − reps)). Both work well in the 1-10 rep range; both overestimate above 10 reps. The tool defaults to the average of the two, which is the most accurate single estimate.
كيفية الاستخدام
-
Enter a weight you actually lifted
A set that challenged you but did not fail. Don't sandbag — use the real number.
-
Enter the rep count
How many clean reps you got. Stop counting at the first one that started to slow or shift form.
-
Pick a formula
Average is the most accurate. Epley tends to estimate slightly higher; Brzycki slightly lower.
-
Read the working weights
50% / 60% / 70% / 80% / 90% of your estimated 1RM for warm-ups and working sets.
أمثلة
Bench press: 5 reps at 100 kg
Average of Epley and Brzycki formulas.
النتيجة: Estimated 1RM ≈ 112.5 kg; 80% = 90 kg; 90% = 101.3 kg
Squat: 3 reps at 140 kg
Epley formula only.
النتيجة: Estimated 1RM ≈ 154 kg; 70% = 107.8 kg; 90% = 138.6 kg
الأسئلة الشائعة
أدوات ذات صلة
حاسبة مؤشر كتلة الجسم
احسب مؤشر كتلة جسمك من الطول والوزن. مجاني، في متصفحك، بدون رفع.
Body Fat Calculator
Estimate body fat percentage using the U.S. Navy circumference method. Tape measure and a few seconds — no scales required.
Calorie Calculator (BMR + TDEE)
Calculate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE). Includes a goal-adjusted daily calorie target.
Macro Calculator
Calculate daily protein, carb, and fat grams from a calorie target. Four common splits: balanced, high-protein, low-carb, and keto.
Pace Calculator
Calculate running or cycling pace from time and distance, or finish time from pace and distance. Supports km and miles.
Last reviewed: 2026-09-25