Getting Stronger
One Rep Max Calculator, 1RM Chart and How to Test It
Your one-rep max (1RM) is the most weight you can lift once with clean form. Most lifters never need to test it: one hard set of 3 to 6 reps gives a close estimate, and the calculator below turns that set into a max and a full table of working weights. This is one of the later Getting Stronger guides and an advanced one. Percentages earn their place after a year or two of simple progression, once adding weight every week has stopped working on its own.
The 1RM chart: reps to percent of max
| Reps you got | That weight is about | Multiply it by | Epley | Brzycki |
|---|---|---|---|---|
| 1 | 100% | 1.00 | 100% | 100% |
| 2 | 95% | 1.05 | 94% | 97% |
| 3 | 93% | 1.08 | 91% | 94% |
| 4 | 90% | 1.11 | 88% | 92% |
| 5 | 87% | 1.15 | 86% | 89% |
| 6 | 85% | 1.18 | 83% | 86% |
| 7 | 82% | 1.22 | 81% | 83% |
| 8 | 80% | 1.25 | 79% | 81% |
| 9 | 77% | 1.29 | 77% | 78% |
| 10 | 75% | 1.33 | 75% | 75% |
| 12 | 70% | 1.42 | 71% | 69% |
| 15 | 64% | 1.57 | 67% | 61% |
Example: 100 kg (220 lb) for 5 reps × 1.15 = about 115 kg (253 lb) estimated max. The middle columns are the average of the two formulas, which is what the calculator uses.
Calculator
Percentage of 1RM chart
This chart goes the other way from the card: pick a percentage, see roughly how many reps it allows to failure and what it is for. Working sets stop a few reps short of that number.
| % of 1RM | Reps to failure, about | Used for |
|---|---|---|
| 100% | 1 | Testing, competition |
| 95% | 2 | Heavy singles, peaking |
| 90% | 4 | Singles and doubles |
| 85% | 6 | Strength work, sets of 2 to 4 |
| 80% | 8 | Strength and muscle, sets of 3 to 6 |
| 75% | 10 | Main volume work, sets of 5 to 8 |
| 70% | 12 | Volume work, sets of 6 to 10 |
| 65% | 15 | Technique, deload weeks |
| 50–60% | 15–20+ | Warm-ups, speed work |
The NSCA's loading guidelines use the same bands: 85% and up for maximal strength in sets of six or fewer, 67 to 85% for muscle in sets of six to twelve. Muscle also grows from lighter loads taken close to failure; a 2017 meta-analysis by Schoenfeld and colleagues found similar growth from loads at or below 60% of max, while heavier loads built more strength. For a bigger 1RM, most main-lift work belongs between 70 and 90%.
Working weights in kilograms, rounded to 2.5 kg:
| % of 1RM | 60 kg | 80 kg | 100 kg | 120 kg | 140 kg | 180 kg |
|---|---|---|---|---|---|---|
| 95% | 57.5 | 75 | 95 | 115 | 132.5 | 170 |
| 90% | 55 | 72.5 | 90 | 107.5 | 125 | 162.5 |
| 85% | 50 | 67.5 | 85 | 102.5 | 120 | 152.5 |
| 80% | 47.5 | 65 | 80 | 95 | 112.5 | 145 |
| 75% | 45 | 60 | 75 | 90 | 105 | 135 |
| 70% | 42.5 | 55 | 70 | 85 | 97.5 | 125 |
| 65% | 40 | 52.5 | 65 | 77.5 | 90 | 117.5 |
| 60% | 35 | 47.5 | 60 | 72.5 | 85 | 107.5 |
Working weights in pounds, rounded to 5 lb:
| % of 1RM | 135 lb | 185 lb | 225 lb | 275 lb | 315 lb | 405 lb |
|---|---|---|---|---|---|---|
| 95% | 130 | 175 | 215 | 260 | 300 | 385 |
| 90% | 120 | 165 | 205 | 250 | 285 | 365 |
| 85% | 115 | 155 | 190 | 235 | 270 | 345 |
| 80% | 110 | 150 | 180 | 220 | 250 | 325 |
| 75% | 100 | 140 | 170 | 205 | 235 | 305 |
| 70% | 95 | 130 | 160 | 195 | 220 | 285 |
| 65% | 90 | 120 | 145 | 180 | 205 | 265 |
| 60% | 80 | 110 | 135 | 165 | 190 | 245 |
How the two formulas work
Both formulas project one set down to a single rep. They come from strength coaches Boyd Epley and Matt Brzycki.
- Epley: 1RM = weight × (1 + reps ÷ 30)
- Brzycki: 1RM = weight × 36 ÷ (37 − reps)
Worked through for a bench press of 225 lb for 5 reps:
| Formula | Sum | Estimated max |
|---|---|---|
| Epley | 225 × (1 + 5 ÷ 30) | 262.5 lb (119 kg) |
| Brzycki | 225 × 36 ÷ 32 | 253 lb (115 kg) |
| Average | (262.5 + 253) ÷ 2 | about 258 lb (117 kg) |
Below 10 reps Epley reads a little higher; at exactly 10 they agree (both multiply by 1.33); above 10 Brzycki climbs faster. Averaging splits the difference. To go the other way, multiply the max by a percentage: 80% of 258 lb is 206 lb, loaded as 205 lb.
When the estimate lies
Every formula assumes reps and percentage relate the same way for everyone and every lift. They do not.
- High reps. Up to 6 reps the two formulas agree within about 4%. Past 10 they split fast. 100 kg (220 lb) for 15 reps gives 150 kg from Epley and 164 kg from Brzycki, a 14 kg (30 lb) gap. At 20 reps it is 167 kg against 212 kg, which means neither is describing anything real. That is why the calculator refuses sets over 15 reps and flags anything over 10.
- Different lifts. At the same percentage, people get more reps on lower-body and machine lifts than on the bench press; Hoeger and colleagues (1990) showed it most clearly on the leg press. For machines and accessories, use rep targets and effort ratings, not a formula.
- Your training history. Some lifters get 8 reps at 80%, others 5. Years of high-rep or endurance work usually make the chart overestimate your max from a set of 8 to 12.
- Sets that were not to failure. If 5 reps was really RPE 7, the formula underestimates you. Add the reps you had left, as the calculator's "reps left" box does. The RPE and reps-in-reserve chart covers rating a set honestly.
LeSuer and colleagues (1997) checked seven equations against measured maxes in college students: close on the bench press and squat, while every equation underestimated the deadlift. Estimates hold up best from low-rep sets and drift as reps rise. The rule: estimate from 3 to 6 reps, accept about 5% error either way, and let the next sessions correct it.
Should you test a true 1RM?
You do not need a tested max to get stronger. An estimate is enough to program from and costs far less fatigue.
| Situation | Test or estimate? |
|---|---|
| Under a year of training, still adding weight most weeks | Neither. Keep using plain progressive overload |
| First percentage program | Estimate from a set of 3 to 5; the block corrects it |
| End of a 12 to 16 week cycle | Test one or two lifts, not all of them in one day |
| Planning a powerlifting meet | Practice heavy singles in training first |
| Back from injury, illness or a long break | Estimate only, for at least two blocks |
| High blood pressure or a heart condition | Check with your doctor first; maximal lifts with a held breath raise blood pressure sharply |
Test when fresh but sharp: the second or third week after a deload week, once you have handled heavy weights again, or in place of the AMRAP set in week 5 of the block below. Never during a deload or at the end of a hard high-volume week.
How to test a true 1RM safely
The NSCA's testing protocol works up through lighter warm-up sets, then aims to find the max within three to five heavy attempts with several minutes between them. This ramp follows that shape for an expected squat max of 140 kg (310 lb), taken from a recent estimate.
| Set | % of expected max | Weight | Reps | Rest after |
|---|---|---|---|---|
| 1 | Empty bar | 20 kg / 45 lb | 10 | 1 min |
| 2 | 40% | 55 kg / 120 lb | 5 | 1–2 min |
| 3 | 60% | 85 kg / 185 lb | 3 | 2 min |
| 4 | 70% | 97.5 kg / 215 lb | 2 | 2–3 min |
| 5 | 80% | 112.5 kg / 250 lb | 1 | 3 min |
| 6 | 90% | 125 kg / 275 lb | 1 | 3–4 min |
| 7 | 95%, first attempt | 132.5 kg / 290 lb | 1 | 3–5 min |
| 8 | 100%, second attempt | 140 kg / 310 lb | 1 | 3–5 min |
| 9 | 102–104%, only if set 8 was RPE 9 or easier | 142.5–145 kg / 315–320 lb | 1 | Done |
Do your normal general warm-up before set 1; the warm-up guide has the short version. Then:
- Set the safeties. Squat in a rack with safety arms just below the bottom position. Bench with a spotter who knows the lift, or safety arms set just below your chest. Never test a bench alone without either.
- Same standard as training. Same depth, pause and lockout. A max with half the depth is not a max.
- Stop at technical failure. Hips shooting up, the bar drifting forward or the back rounding ends the test: the last clean single is your number.
- Jump less as you get closer. The NSCA protocol adds 5 to 10% between attempts on lower-body lifts and 2 to 4% on upper-body lifts; the 7.5 kg (20 lb) jump from set 7 to set 8 sits in that range. Past 100%, go smaller: 2.5 to 5 kg (5 to 10 lb) on squat and deadlift, 1 to 2.5 kg (2.5 to 5 lb) on bench and press.
- Two misses end it. After a miss, rest and make one more attempt 2.5 kg (5 lb) lighter, or call it. A second miss is fatigue, not information.
Test one or two lifts per day, and treat the next two or three days as easy training. A heavy test costs more recovery than the few reps suggest.
Using percentages: a 6-week block
With a max in hand, you can set every week's weight in advance. This is our own six-week block for one main lift, on the 5 + 1 pattern from the deload guide. It replaces the first lift of a day you already train, such as a heavy day on an upper/lower split; the rest of the session stays as it is. The example uses a 140 kg (310 lb) squat max, rounded to 2.5 kg, with pounds converted from the kilogram load.
| Week | Sets × reps | % of max | 140 kg / 310 lb max | Target effort |
|---|---|---|---|---|
| 1 | 4 × 6 | 75% | 105 kg / 230 lb | RPE 6–7 |
| 2 | 4 × 5 | 80% | 112.5 kg / 250 lb | RPE 7 |
| 3 | 4 × 4 | 85% | 120 kg / 265 lb | RPE 8 |
| 4 | 3 × 2 | 90% | 125 kg / 275 lb | RPE 8 |
| 5 | 1 set of as many reps as possible, stop at RPE 9; then 2 × 3 | 85% | 120 kg / 265 lb | RPE 9 on the first set |
| 6 | 3 × 5 (deload) | 65% | 90 kg / 200 lb | RPE 5 |
Weeks 1 to 4 trade reps for weight while effort climbs slowly. Week 5 is the check: 85% is about a 6-rep weight, so if the max is right, the as-many-reps-as-possible (AMRAP) set stopped at RPE 9, one rep left, lands on 5 reps. The table below counts that rep left.
| AMRAP at 120 kg (265 lb) | What it means | Next block's max |
|---|---|---|
| 4 or fewer | Max set too high, or fatigue building | Drop 5%: 132.5 kg (292 lb), and run the checks in the strength plateau guide |
| 5 | The max fits | Keep 140 kg (310 lb) |
| 6–7 | A little stronger; formulas say 146 to 150 kg (320 to 330 lb) | Add 2.5 kg (5 lb): 142.5 kg (315 lb) |
| 8 or more | Formulas say 155 kg (340 lb) or more | Add 5 kg (10 lb) on squat and deadlift, 2.5 kg (5 lb) on bench and press: 145 kg (320 lb) |
The caps are deliberate. 120 kg × 8 with one rep left counts as 9 reps: 156 kg from Epley and 154 kg from Brzycki. But one AMRAP set is one data point, and a max raised too far shows up as missed reps in the next week 3. Taking 5 kg (10 lb) and beating it beats taking 15 kg (33 lb) and failing.
If week 3 lands at RPE 9 or harder block after block, program from a training max of 90% of your real max, an idea popularized by Jim Wendler's 5/3/1: run the same table from 126 kg, about 125 kg (275 lb). This block is a simple form of linear periodization, and a 2017 meta-analysis by Williams and colleagues found periodized programs produced larger 1RM gains than non-periodized ones. The periodization guide shows how to string blocks together across a year.
If the percentages do not fit
A percentage is the starting point; your effort rating on the day is the correction.
| If | Then |
|---|---|
| Week 1 sets feel like RPE 8 or harder | The max is too high. Take 5% off for the rest of the block |
| Every set through week 3 feels like RPE 5 or easier | The max is low. Leave it; the week 5 AMRAP will raise it |
| One slow day at a weight that moved easily last week | Do the reps, skip the last set if it would hit RPE 9.5. One session is noise |
| Two sessions in a row miss the target effort by 1.5 points or more | Cut the max by 5%, or take the deload early |
| Squat moving, bench stuck | Each lift has its own max and AMRAP. Adjust only the one that stalled |
| Two blocks with no gain in the AMRAP | Check sleep, food and weekly sets, then change the block structure |
None of this works without a log: weight, reps and how hard it felt, every session. Without it you cannot tell a wrong max from a bad night's sleep.
Questions people ask
How do I calculate my one rep max?
Take a set of 3 to 6 reps to failure or close to it. Epley: weight × (1 + reps ÷ 30). Brzycki: weight × 36 ÷ (37 − reps). The calculator above averages both.
Which 1RM formula is most accurate?
None is best for everyone. Under about 6 reps the common formulas land within about 4% of each other, so picking a good set matters more than picking a formula.
How often should I test my 1RM?
Two to four times a year at most, and many advanced lifters never do. An AMRAP set at the end of each block gives most of the information for a fraction of the fatigue.
Is testing your one rep max dangerous?
It leaves less margin for error than normal training. With a full warm-up, safety arms or a spotter and a rule to stop at the first form break, a healthy, experienced lifter can test safely. Beginners should not.
What percentage of my 1RM should I lift?
For strength, 75 to 90% in sets of 2 to 6. For muscle, 65 to 80% in sets of 6 to 12, though lighter loads work when sets go close to failure. Warm-ups and deloads, 50 to 65%.
Can I use the calculator for dumbbells or machines?
Only as a rough guide. Machine lifts often allow far more reps at the same percentage. Track rep maxes, such as your best set of 10, instead.
Where these numbers come from
The Epley formula comes from Boyd Epley's 1985 poundage chart for the University of Nebraska strength program. The Brzycki formula is from Matt Brzycki, Strength testing: predicting a one-rep max from reps-to-fatigue (Journal of Physical Education, Recreation and Dance, 1993). The seven-equation comparison is LeSuer, McCormick and Mayhew, The accuracy of prediction equations for estimating 1-RM performance in the bench press, squat, and deadlift (Journal of Strength and Conditioning Research, 1997). The difference in reps between exercises at the same percentage is from Hoeger and colleagues (Journal of Applied Sport Science Research, 1990).
The loading bands and testing protocol follow the NSCA's Essentials of Strength Training and Conditioning. The load result is Schoenfeld and colleagues, Strength and hypertrophy adaptations between low- vs. high-load resistance training: a systematic review and meta-analysis (Journal of Strength and Conditioning Research, 2017). The periodization result is Williams and colleagues, Comparison of periodized and non-periodized resistance training on maximal strength: a meta-analysis (Sports Medicine, 2017). The training max is credited to Jim Wendler's 5/3/1. The six-week block is our own.
Take the plan to the gym