Calculate Your 1-Rep Max

This 1RM calculator uses weight and reps1 performed to estimate your one rep max.

1RM Formula

The formula used for this calculation is: 1RM = Weight in pounds/(1.0278-(.0278 x reps1))

Reps performed
Weight in pounds
or
Weight in kilograms

Calculating Multiple Reps from your 1RM

This table below helps you figure out what weight to use (+/- 5 pounds) for a goal number of reps based on your 1RM. For example, if your 1RM is 250 and you wanted to do a set of 8 reps, multiple 250 by .786 to get 196.5 for a weigh range of 191.5 - 201.5 pounds for your 8 rep set. If you've been doing lighter weight for more reps (10+), or heavier weight for fewer reps (3 or less), it won't be as accurate.

Enter you 1RM and the coefficient based on your rep goal into the form below and click calcualte.

1RM weight in pounds
or
1RM weight in kilograms
Coefficint based on rep goal
Reps CoEfficient
1 1.00
2 .943
3 .906
4 .881
5 .856
6 .831
7 .807
8 .786
9 .765
10 .744
Reps CoEfficient
11 .723
12 .703
13 .688
14 .675
15 .662
16 .650
17 .638
18 .627
19 .616
20 .606

Another Chart for your 1-rep Max

Here's another chart with values you can use to calculate your one rep max based on the exercise and reps.


1RM weight in pounds
Repetitions Squat Benchpress Deadlift
1 1.0 1.0 1.0
2 1.0475 1.035 1.065
3 1.13 1.08 1.13
4 1.1575 1.115 1.147
5 1.2 1.15 1.164
6 1.242 1.18 1.181
7 1.284 1.22 1.198
8 1.326 1.255 1.232
9 1.368 1.29 1.232
10 1.41 1.325 1.24

A Formula for your 1-rep Max

This formual estimates your one rep max based on reps and weight used. Enter reps and the weight into the form beliow click calculate. ((Reps x .033) + 1) x Weight

Reps
Weight in pounds