One Rep Max Calculator
Enter the weight and reps of an all-out set and get your estimated 1RM — from the RPE chart or any of the classic formulas, all compared side by side. Free, lb and kg, no login.
Reps of an all-out set (nothing left in the tank).
The app default — turns your reps and RPE into a percentage of your max, built for autoregulated training where you rate how hard each set felt.
Enter the weight you lifted for 5 reps all-out.
Quick reference: barbell rep-max table
Estimated 1RM when the set was all-out (RPE 10). Had reps left in the tank? Use the calculator above — it adjusts for RPE.
| Weight lifted | × 3 | × 5 | × 8 | × 10 |
|---|---|---|---|---|
| 95 lb | ~105 | ~110 | ~120 | ~130 |
| 135 lb | ~145 | ~155 | ~170 | ~185 |
| 185 lb | ~200 | ~215 | ~235 | ~250 |
| 225 lb | ~245 | ~260 | ~285 | ~305 |
| 275 lb | ~300 | ~320 | ~350 | ~370 |
| 315 lb | ~340 | ~365 | ~400 | ~425 |
| 365 lb | ~395 | ~425 | ~465 | ~495 |
| 405 lb | ~440 | ~470 | ~515 | ~550 |
| 455 lb | ~495 | ~525 | ~580 | ~615 |
| 495 lb | ~535 | ~575 | ~630 | ~670 |
Estimates from the RPE percentage chart. Working in kilos? The calculator shows every result in both units.
Questions
How is a one rep max estimated from reps?+
Every method encodes the same idea: the more reps you can do at a weight, the smaller that weight is as a fraction of your max. Enter an all-out set — say 225 × 5 — and the formula works backwards to the single. Sets of 2–6 reps estimate most reliably; past 10 reps every formula gets fuzzy.
Which formula is most accurate?+
They agree within a few pounds at low reps and drift apart as reps climb. Brzycki tends to fit heavy triples and fives best; Epley is the most widely used all-rounder. That's exactly why this calculator shows them side by side — the spread itself tells you how confident to be.
What if my set wasn't truly all-out?+
Classic formulas assume nothing was left in the tank. If you had a rep or two in reserve, use the RPE calculator instead — it takes RPE into account so an honest RPE 8 set still gives a good estimate.
Should I actually test my 1RM?+
Estimates are for planning; testing is for meets and milestones. Most training decisions only need a good estimate, which is why coaches program off estimated maxes and save true max attempts for when they count.
Can I save my max and program off it?+
That's the app: a free account saves each lift's 1RM with dated history, turns reps + RPE into working weights, builds warm-up ramps, and shows exactly which plates to load — using whichever calculation method you pick in Settings.
More free tools: RPE calculator · Warm-up sets · Plate loader · RPE chart · Bench max · Squat max · Deadlift max
Save your maxes — stop retyping them every session
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