A walkthrough, end to end.
- 1
Enter the weight you lifted and the number of clean reps you completed.
- 2
The calculator runs three popular 1RM formulas and averages them.
- 3
See percentage-based training loads from 50% to 95% of 1RM for programming sets and reps.
1RM formulas
Epley (1985), Brzycki (1993), and Lombardi (1989) are the most commonly cited. They diverge slightly above 8 reps; below that they agree within ~2%. Treat the average as a working estimate and adjust based on actual gym performance.
What you can do with this.
Programming with %1RM
Strength: 80–95% × 1–5 reps. Hypertrophy: 65–80% × 6–12. Endurance: <65% × 12+. Most periodized programs (5/3/1, Texas Method) prescribe loads as %1RM.
Estimating 1RM safely
Test in the 3–5 rep range, not 8+. Above 8 reps the formulas overestimate by 5–10%. A 5RM is the sweet spot — recent, repeatable, and accurate.
Tracking strength progress
Estimate 1RM weekly from your top set. Watch for plateaus across 3+ weeks — that's the signal to deload or change exercise variation.
Bench press 1RM calculator
Bench tends to overestimate via Epley above 6 reps because triceps fatigue faster than chest. For bench specifically, Brzycki (the conservative formula) is the better default.
Squat 1RM calculator
Squat tolerates higher rep tests well — leg endurance scales with strength. A 5RM squat estimate is typically within 2% of the true 1RM for trained lifters.
Deadlift 1RM calculator
Deadlift estimates often UNDER-shoot true 1RM because grip and CNS readiness limit submaximal sets more than maxes. Add ~3–5% to formula estimates for honest deadlift targets.
Picking warm-up weights from 1RM
A common ramp: 40% × 5, 60% × 3, 75% × 2, 85% × 1, then your work set. Plug your 1RM in and the calculator gives you the loads — saves the gym-floor mental math.
5/3/1 and Texas Method weights
Both programs prescribe by training max (~90% of 1RM). Compute 1RM here, multiply by 0.90 for TM, then read straight off the percentage table for week-to-week loads.
1RM calculator 2026 — what's current
Velocity-based training (VBT) measurements from devices like Vitruve and Enode give per-rep velocity that infers 1RM more accurately than rep-based formulas, but they cost ~$300. The classic formulas remain the no-equipment standard.
Frequently asked.
Only with a spotter, after a long warm-up, and not too often. Estimating from a 3–5RM is safer and almost as accurate.
They were derived from different lifters and lifts. Brzycki tends to be conservative; Epley aggressive at high reps. Use the average for general programming.
All three are commonly used for any compound lift. They tend to underestimate deadlift 1RM and overestimate bench. Calibrate by lift over time.
Every 8–12 weeks during structured programs; every 4–6 weeks during peaking blocks. Real 1RM testing is fatiguing — between tests, estimate from your top sets to track trend.
Not directly — percentages are relative to YOUR 1RM. But bodyweight shifts (cuts, bulks) usually shift 1RM proportionally; recompute every few weeks during a phase.
No. Calculations run entirely in your browser. There's no server processing, no analytics on inputs, no cookies storing your numbers.