Guide / Lifting
1RM percentage chart
Every percentage of a one rep max from 50% to 100%, with the reps two common formulas predict at each step. Worked weights follow for a 225 lb and a 100 kg max.
How to calculate 1RM
Your one rep max (1RM) is the heaviest weight you can lift once with good form. Testing it directly means working up to a true limit. Most lifters estimate it instead, from a hard set of several reps.
This site uses two formulas for that. Epley multiplies the weight by 1 + reps ÷ 30. Brzycki multiplies it by 36 ÷ (37 − reps). A set of 200 lb for 6 reps gives 240 lb with Epley and about 232 lb with Brzycki.
Each formula also runs in reverse. Pick a percentage of your max, and you can solve for how many reps that load should allow before failure. That reverse calculation is what fills the chart below.
Percentage of 1RM and predicted reps
Shaded: 70–85%| % of 1RM | Reps to failure (Epley) | Reps to failure (Brzycki) |
|---|---|---|
| 100% | 1 | 1 |
| 95% | 1.6 | 2.8 |
| 90% | 3.3 | 4.6 |
| 85% | 5.3 | 6.4 |
| 80% | 7.5 | 8.2 |
| 75% | 10.0 | 10.0 |
| 70% | 12.9 | 11.8 |
| 65% | 16.2 | 13.6 |
| 60% | 20.0 | 15.4 |
| 55% | 24.5 | 17.2 |
| 50% | 30.0 | 19.0 |
Computed from the same two formulas the 1RM calculator runs. Solved for reps, they read Epley reps = 30 × (1 ÷ fraction − 1), Brzycki reps = 37 − 36 × fraction. Shown to one decimal. At 100% both read 1 rep, since the calculator treats a single as the max itself. Reps beyond about 10 are outside the range either formula handles well.
Reading the chart
Find the percentage a program asks for. The two rep columns tell you roughly how many reps that load allows when every rep is pushed to the limit. At 85%, Epley expects about 5 reps and Brzycki about 6.
The decimals are the formulas talking, not a target. Round down to a whole rep. Most sets in a program also stop short of failure, so the reps you are asked to do will usually sit below these numbers.
The calculator page shows a shorter table with a "typical reps" range beside each percentage. Those ranges are rounded, practical guidance. The columns here are the raw formula output, so the two won't match cell for cell.
Worked example: 225 lb and 100 kg
Shaded: 70–85%| % of 1RM | 225 lb max | 100 kg max |
|---|---|---|
| 100% | 225 lb | 100 kg |
| 95% | 214 lb | 95 kg |
| 90% | 203 lb | 90 kg |
| 85% | 191 lb | 85 kg |
| 80% | 180 lb | 80 kg |
| 75% | 169 lb | 75 kg |
| 70% | 158 lb | 70 kg |
| 65% | 146 lb | 65 kg |
| 60% | 135 lb | 60 kg |
| 55% | 124 lb | 55 kg |
| 50% | 113 lb | 50 kg |
Weight = max × percentage, rounded to the nearest whole pound or kilogram, as the calculator rounds. Round again to the plates in your gym.
Take the 225 lb lifter. A program that calls for 4 sets of 6 at 80% puts 180 lb on the bar. The chart says 80% allows about 7 or 8 reps to failure. So 6 reps leaves one or two in reserve, which is a sensible place for a working set to finish.
The kilogram column is simpler, because a 100 kg max makes every percentage read straight across. That also makes it a handy mental check. If your max is 140 kg, 75% is three quarters of it: 105 kg.
What the percentage ranges are used for
Strength programs tend to group percentages into rough bands. The bands below are general convention, not fixed rules. Different coaches draw the lines a few percent apart.
- Around 85% and above: heavy sets of 1 to 5 reps, aimed mainly at maximal strength.
- Roughly 65% to 85%: moderate sets of about 6 to 12 reps, the usual home of muscle-building work.
- Below about 65%: lighter sets of 12 or more reps for muscular endurance, technique practice, warm-ups and easier weeks.
These bands overlap with the rep columns in the chart, and that is no coincidence. A load you can lift 3 times is a strength load almost by definition. A load you can lift 15 times can't be.
Programs write percentages instead of fixed weights so the plan scales with the lifter. It also means an out-of-date max quietly skews every session. Re-estimate after each training block.
When the estimates fail
Both formulas are curve fits. They describe an average lifter, and they work best on a narrow kind of set. Several things pull a real lifter away from the chart.
High reps
The further a set runs past 10 reps, the less it says about a single. Breathing, grip and local fatigue start ending the set before strength does. Look at the 50% row: Epley predicts 30 reps and Brzycki 19. Two formulas that far apart are both guessing.
Fatigue
A set done at the end of a long session, or on a short night's sleep, ends early. The formula reads that as a lower max. Use a set done fresh, early in a workout, after a proper warm-up.
Technique
On a lift you are still learning, form often breaks down before the muscles give out. The set stops for a technical reason, and the estimate comes out low. The reverse can happen too. A lifter with polished technique may grind out a heavy single the chart says they shouldn't have.
Untrained lifters
Beginners often can't yet judge where failure is. Many stop sets with several reps left, which makes the estimate low. Their real max also climbs quickly in the first months, so last month's number is already stale. For newer lifters, the rep column is a rough guide and nothing more.
Why Epley and Brzycki diverge
The two formulas are different shapes. Epley is a straight line: each extra rep adds the same fixed slice, one thirtieth of the weight. Brzycki is a curve whose slope steepens as reps rise, because its denominator shrinks toward zero.
The shapes cross at exactly 10 reps. Below that, Epley gives the higher estimate of your max. Above it, Brzycki pulls ahead, and the gap grows fast. For 225 lb lifted 15 times, Epley estimates 338 lb and Brzycki 368 lb.
In the chart that shows up the other way round. Under 75%, Epley predicts more reps than Brzycki. Above 75%, it predicts fewer. Both formulas agree best in the 3 to 10 rep zone, which is one more reason to estimate from a set in that range.
Safety with heavy singles
Percentages near the top of the chart are close to your limit. Treat them with care.
- Warm up in steps. Climb through several lighter sets before a heavy one, cutting reps as the weight rises.
- Use a spotter or safeties. On the bench press and squat, set the rack's safety arms or pins at the right height, or have a spotter who knows the lift.
- Stop when form breaks. A rep you can only finish by changing your technique is a good place to end the set.
- Leave the top of the chart for planned days. Work at 95% and above belongs where a program schedules it, not in every session.
This guide is general information about how two estimation formulas behave. It is not medical advice and not a training prescription. The rep figures are what the formulas predict for an average lifter, and yours may differ. If you have an injury, a medical condition, or pain during lifting, get advice from a qualified professional before training heavy.
Common questions
Why does the chart show reps with a decimal point?
Because the formulas are smooth curves, and solving them for reps rarely lands on a whole number. Nobody lifts 7.5 reps. Round down to the whole rep below, since the chart describes a set taken to failure and you will usually want a rep or two in reserve.
Why do Epley and Brzycki agree exactly at 10 reps?
It falls out of the arithmetic. At 10 reps Epley multiplies the weight by 1 + 10/30, and Brzycki multiplies it by 36/27. Both come to 4/3, so both put 10 reps at exactly 75% of the max. Below 10 reps Epley gives the higher estimate; above 10, Brzycki does.
Does the same percentage chart work for every lift?
The formulas use one curve for every exercise, so the chart does too. Real lifters drift from that curve, and the drift is not the same on every lift. Treat the rep column as a first guess, then log what you actually manage at a given percentage on each lift and trust that record over the chart.
Should I take percentages from a tested max or an estimated one?
Either works if you stay consistent. A recent tested max is the more direct number. An estimate from a hard set of 3 to 8 reps is close enough for ordinary programming, and it avoids the fatigue and risk of a true single. Mixing the two between training blocks makes week-to-week comparisons harder.
How should I round a percentage to the plates I have?
Round to the nearest load you can build on the bar. With 5 lb or 2.5 kg jumps, that moves the weight by a pound or two at most, which is well inside the error of any estimated max. On heavy singles above 90%, rounding down is the cautious choice.