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One Rep Max Calculator

Estimate your one rep max for the bench press, squat, deadlift or any lift from the weight and reps you did, and get your training weights.

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  • Numbers stay in your browser

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Estimate Your One Rep Max

Lift
lb
reps
Reps:
Reps you could still have done (optional)
Unit
Round to
Your estimated bench press one rep max is
259.9 lb
From 225 lb for 5 reps. The seven formulas range from 253.1 to 267.8 lb. Your set was 86.6% of your max.
  • Estimated 1RM259.9 lb
  • Formula range253.1 – 267.8 lb
  • Your set is86.6% of 1RM

Training weights

  • 50%129.9 lb
  • 60%155.9 lb
  • 70%181.9 lb
  • 80%207.9 lb
  • 90%233.9 lb

The estimate is most reliable for sets of 2 to 10 reps. Heavy sets near your max are best done with a spotter. These are estimates, not a prescription: ask a coach or doctor before testing a true max.

About One Rep Max Calculator

Your one rep max (1RM) is the heaviest weight you could lift once with good form. This calculator estimates it from a lighter set, using seven well-known formulas and their average, so you do not have to test a true max.

Epley: 1RM = Weight × (1 + Reps ÷ 30)

Reps and % of 1RM

Reps% of 1RM
1100%
391.5%
586.6%
880.2%
1076.3%
1272.7%

The average of the seven formulas. The full chart is below.

Lift Safely

  • Warm up first, with lighter sets
  • Use a spotter or safety bars for heavy sets
  • Sets of 2 to 10 reps give the best estimate
  • Estimating is safer than testing a true max

Rep Max Chart

How much weight for 5 reps? The percent of your one rep max for each number of reps, and the weight in your own numbers (for a 1RM of 259.9 lb).

Reps% of 1RMWeight (lb)
100%259.9
94.3%245
91.5%237.7
88.9%231.1
86.6%225
84.4%219.2
82.2%213.7
80.2%208.4
78.2%203.2
76.3%198.3
74.5%193.5
72.7%188.8
70.9%184.2
69.1%179.7
67.4%175.2

Rep max means the most reps you can do with a weight. Click a number of reps to see it in the calculator.

The Seven Formulas

Each formula gives a slightly different answer. Here is 225 lb for 5 reps in each.

FormulaEquation1RM (lb)
Epleyw × (1 + r ÷ 30)262.5
Brzyckiw × 36 ÷ (37 − r)253.1
Lander100w ÷ (101.3 − 2.67123 r)255.8
Lombardiw × r^0.10264.3
O'Connerw × (1 + 0.025 r)253.1
Mayhew100w ÷ (52.2 + 41.9 e^(−0.055 r))267.8
Wathen100w ÷ (48.8 + 53.8 e^(−0.075 r))262.3
w is the weight, r the reps, and e is the number 2.718. The average is the headline answer, and the range shows how much the formulas disagree. At 1 rep the answer is just the weight.

Training Zones

A common guide to the percent of your 1RM, the reps and the goal, with your weights.

Goal% of 1RMRepsWeight (lb)
Max strength90–100%1–3233.9 – 259.9
Strength and size75–85%6–12194.9 – 220.9
Muscle endurance65–75%12–20168.9 – 194.9
Warm-up and speed50–65%20 or more129.9 – 168.9

Coaches use slightly different ranges, so treat these as a starting point.

RPE and Reps Left

RPE (rate of perceived exertion) says how hard a set was, from 10 (nothing left) down.

RPEReps leftMeaning
10NoneA true maximum for that many reps
91You could do 1 more rep
82You could do 2 more reps
73You could do 3 more reps
64You could do 4 more reps

Choose the reps you could still have done in the calculator to improve the estimate for sets that were not to failure.

1 Rep Max Chart

Your one rep max for common weights and reps. What is 365 × 4? Read across the row for 365.

Weight1 rep2 reps3 reps4 reps5 reps6 reps8 reps10 reps
135 lb
185 lb
225 lb
275 lb
315 lb
365 lb
405 lb

Whole pounds, from the average of seven formulas. Click a number to see it in the calculator.

Try an Example

Pick one to fill in the calculator and see its answer.

ExampleResult
259.9 lb
410.3 lb
344.3 lb
124.7 kg
242.4 lb
273.6 lb

Click an example to put it into the calculator.

Good to know

  • A 1RM is different for every lift, so work it out for the bench press, the squat and the deadlift separately.
  • Sets of 2 to 10 reps are the most reliable. The more reps in the set, the less accurate the estimate.
  • Use clean reps only, with the same form and depth on every rep, and stop when your form breaks down.
  • For dumbbells, use the same choice every time: the weight of one dumbbell, or both added together.

What is included

  • 1RM for the bench press, squat, deadlift and other lifts
  • Seven formulas, their average and the range
  • Reps left in reserve (RPE) for sets not to failure
  • Weight for any number of reps, and a rep max chart
  • Training zones and a 1 rep max chart
  • Pounds or kilograms, copy link and print

Important to know

Your numbers stay in your own browser and are never sent anywhere. These are estimates, and real lifts vary with form, rest and the day. Warm up, use a spotter, and ask a coach or doctor before testing a true one rep max.

Use this free one rep max calculator to estimate your 1RM for the bench press, squat, deadlift or any lift from the weight and the reps you did. The answer is the average of seven well-known formulas, with their range, the share of your max that your set was, and your training weights from 50% to 90%. Tell it how many reps you had left to improve the estimate for sets that were not to failure, or switch to the Weight for Reps tab to find the weight for a number of reps from your max. Tables show a rep max chart, the seven formulas, training zones, RPE, and a 1 rep max chart for common weights. It works in pounds and kilograms, it is free and instant, and your numbers stay in your browser.

What is a one rep max?

Your one rep max (1RM) is the heaviest weight you can lift for a single clean repetition of an exercise, such as the bench press, the squat or the deadlift. It is a measure of maximal strength, and it is used to set training weights as a percentage of your max. Because every lift is different, you have a separate 1RM for each one. Testing a true max is hard on the body and risky without a spotter, so most people estimate it from a lighter set instead.

How to calculate your one rep max

Lift a weight for as many clean reps as you can, ideally between 2 and 10, and enter the weight and the reps. The calculator works out the 1RM with seven well-known formulas and shows their average. Each formula multiplies your weight by a number that grows with the reps. The simplest is the Epley formula.

Example: a bench press of 225 lb for 5 reps
Epley: 1RM = 225 × (1 + 5 ÷ 30) = 262.5 lb
Brzycki: 1RM = 225 × 36 ÷ (37 − 5) = 253.1 lb
The seven formulas give between 253.1 and 267.8 lb, and their average is 259.9 lb. Your set of 5 reps was 86.6% of that max.

The seven formulas

The calculator uses Epley, Brzycki, Lander, Lombardi, O’Conner, Mayhew and Wathen. They agree closely for sets of a few reps and drift apart as the reps grow, because they were built from different groups of lifters. No formula is the best for everyone, so the average is the headline answer and the range shows how much they disagree. You can also pick a single formula in the Formula box. With 1 rep the answer is simply the weight you lifted.

How many reps should you use?

Sets of 2 to 10 reps give the most reliable estimate. Below that the weight is already close to your max, and above about 10 reps tiredness and pacing make the result less accurate, so the calculator tells you when a set has more than 10 reps. Use clean reps only, with the same form and depth on every rep.

Bench press, squat and deadlift max

Choose the lift at the top of the calculator and the answer is written for it, for example your estimated bench press one rep max. The maths is the same for any barbell lift, and it works best for big compound lifts such as the bench press, squat, deadlift and overhead press. A squat of 365 lb for 4 reps gives a 1RM of about 410 lb, and a deadlift of 315 lb for 3 reps about 344 lb. For weighted dips and pull-ups, enter your bodyweight plus the added weight.

Reps in reserve and RPE

If you stopped a set before failure, tell the calculator how many more reps you could have done. It adds them to the reps you did before working out the max. RPE (rate of perceived exertion) is the same idea on a scale: RPE 10 means nothing left, RPE 9 about 1 rep left, RPE 8 about 2, RPE 7 about 3. Doing 225 lb for 5 reps with 2 left is treated like 7 reps, which gives a 1RM of about 274 lb.

The weight for a number of reps

You can also go the other way. With a 1RM of 260 lb, the weight for 5 reps is 260 ÷ 1.155 = about 225 lb, which is 86.6% of your max. The Weight for Reps tab does this, and the Rep Max Chart lists the percent and the weight for 1 to 15 reps: 3 reps is about 91.5% of your 1RM, 8 reps about 80.2% and 10 reps about 76.3%.

Training zones and a training max

Coaches use your 1RM to choose weights. A common guide is 90 to 100% of your max for 1 to 3 reps to build maximal strength, 75 to 85% for 6 to 12 reps for strength and size, and 65 to 75% for 12 to 20 reps for muscle endurance. The ranges vary a little from coach to coach. Some programs use a training max, often 85 to 90% of your 1RM, to leave room to progress.

Pounds and kilograms

The formulas work the same in pounds or kilograms, so switching units only changes the numbers. 1 kg is 2.20462 lb, so 225 lb is 102.1 kg. The calculator converts your weights when you press the unit buttons, and you can round the results to the plates you have, such as 2.5 or 5 lb, or 1 or 2.5 kg.

Calculators that go with this one

To plan your running, use the Pace Calculator. To plan your food, see the Calorie Calculator, and to track your body, the BMI Calculator, the Body Fat Calculator and the Ideal Weight Calculator.

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Frequently Asked Questions

What is a one rep max (1RM)?

It is the heaviest weight you can lift for one clean repetition of an exercise. You have a different 1RM for each lift. It is used to set training weights as a percentage of your max, and it is usually estimated from a lighter set rather than tested.

How do I calculate my one rep max?

Lift a weight for as many clean reps as you can, then enter the weight and the reps. With the Epley formula the 1RM is the weight × (1 + reps ÷ 30), so 225 lb for 5 reps is 225 × 1.167 = 262.5 lb. The calculator uses seven formulas and shows their average, which is 259.9 lb for the same set.

Which one rep max formula is the most accurate?

None is the best for everyone. Epley and Brzycki are the most used, and they agree closely for sets of a few reps. That is why the calculator shows the average of seven formulas and their range. You can also choose a single formula in the Formula box and keep using it so your numbers stay comparable.

How many reps should I use for the estimate?

Use a set of 2 to 10 reps. The estimate is most reliable there, and it gets less accurate with more reps. Use clean reps only, and stop when your form breaks down.

How do I estimate my max bench press?

Choose Bench press, enter the weight you lifted and how many reps you did, and press Calculate 1RM. For example, a bench press of 225 lb for 5 reps gives an estimated max of about 260 lb. The same maths works for any barbell lift.

How do I estimate my max squat or deadlift?

Choose Squat or Deadlift and enter the weight and reps. A squat of 365 lb for 4 reps gives about 410 lb, and a deadlift of 315 lb for 3 reps about 344 lb. Estimates are best for sets of 2 to 10 reps.

What are reps in reserve and RPE?

Reps in reserve are the reps you could still have done when you stopped. RPE is the same idea on a scale of 10: RPE 10 is nothing left, RPE 9 about 1 left, RPE 8 about 2 and RPE 7 about 3. Choose the reps left in the calculator and it adds them to your reps before working out the max.

How do I find the weight for a number of reps?

Use the Weight for Reps tab: enter your 1RM and the reps you want. The weight is your 1RM divided by the multiplier for those reps. With a 260 lb max, 5 reps is about 225 lb and 8 reps about 208.5 lb. The Rep Max Chart lists 1 to 15 reps.

What percent of my 1RM should I train at?

A common guide is 90 to 100% for 1 to 3 reps (maximal strength), 75 to 85% for 6 to 12 reps (strength and size), 65 to 75% for 12 to 20 reps (muscle endurance) and 50 to 65% for warm-ups and speed work. Coaches use slightly different ranges, so treat these as a starting point.

What is a training max?

Some programs use a training max instead of your true 1RM, often 85 to 90% of it, and work out all weights from that. It leaves room to progress and keeps the heavy sets a little easier. Enter your estimated 1RM, then take that percentage.

Is it safe to test a true one rep max?

Testing a true max is hard on the body and carries more risk of injury, especially for beginners. Estimating from a lighter set is safer and usually good enough to plan training. If you do test, warm up well, use a spotter or safety bars, and ask a coach or doctor first.

Can I use it for dumbbells, pull-ups or dips?

Yes. For dumbbells, use either the weight of one dumbbell or both added together, and keep the same choice every time. For weighted pull-ups and dips, enter your bodyweight plus the added weight. Estimates work best for big compound lifts.

What does 365 × 4 mean?

It means 365 lb lifted for 4 reps. That set gives an estimated one rep max of about 410 lb. The 1 Rep Max Chart lists the estimate for common weights and reps, so you can read it straight off.

How do I change pounds to kilograms?

Press the lb or kg button in the calculator and your weights are converted. By hand, divide pounds by 2.20462 to get kilograms, so 225 lb is 102.1 kg, and multiply kilograms by 2.20462 to get pounds.

How often should I re-test my 1RM?

Every few weeks of steady training, such as every 4 to 8 weeks, is common. Estimating from a recent hard set is quick, so you can check your progress as often as you like and re-set your training weights.

Are my numbers saved or shared?

No. The calculation happens in your browser, and the numbers you enter are not stored or sent to any server. A link you copy keeps the numbers after the # sign, which browsers never send to a server.