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How much weight should I lift?
Lift a weight that leaves 1 or 2 reps in the tank at your target reps. Pick the exercise and enter one recent set with the reps you had left, and the calculator gives the weight for the reps you want, rounded to the plates or pin stack you will use. If you have never done the lift, it tells you where to start.
Example result
55kg
2
From 60 kg × 8 with 2 in reserve. Loads round to 2.5 kg steps.
| Reps | Weight |
|---|---|
| 6 | 62.5 kg |
| 8 | 60 kg |
| 10 | 55 kg |
| 12 | 52.5 kg |
How much to lift: four examples
A first-timer, a machine, a heavy barbell lift and a plate-loaded sled, in pounds and kilos.
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Example 1
Never squatted before
A complete beginner walking up to the squat rack for the first time.
- Exercise
- Barbell Back Squat
- Reps you want per set
- 8
- Test set45 lb
Squat the empty bar for as many smooth reps as you can while about 2 feel left. Enter that set, and the calculator turns it into the weight for your sets of 8.
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Example 2
Lat pulldown, more reps
An intermediate lifter who pulled 50 kg for 8 with 2 reps left and wants to switch to sets of 12.
- Exercise
- Lat Pulldown
- Test weight
- 50 kg
- Reps you did
- 8
- Reps in reserve
- 2
- Reps you want per set
- 12
- Working weight for 12 reps45 kg
- Reps in reserve2
Four more reps cost one pin. Machines and cables move in bigger steps than plates, so when the next pin is too far, add reps first and move the pin once all your sets reach 12.
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Example 3
Deadlift sets of 6 from a set of 5
A lifter who pulled 225 lb for 5 with 2 left in the tank and wants a working weight for sets of 6.
- Exercise
- Barbell Deadlift
- Test weight
- 225 lb
- Reps you did
- 5
- Reps in reserve
- 2
- Reps you want per set
- 6
- Working weight for 6 reps225 lb
- Reps in reserve1
RIRLift runs deadlift sets with 1 rep left, so one extra rep on the target costs nothing here: the same 225 lb. Heavy lifts don't need a big drop to change the rep target.
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Example 4
Leg press after a set to failure
A woman who leg-pressed 120 kg for 10 and couldn't get an 11th, and wants to train with sets of 10.
- Exercise
- Leg Press
- Test weight
- 120 kg
- Reps you did
- 10
- Reps in reserve
- 0
- Reps you want per set
- 10
- Working weight for 10 reps112.5 kg
- Reps in reserve2
Same reps, 2 left instead of none: 7.5 kg lighter. Every set then ends hard but clean, and the 120 kg comes back once all of them reach 12.
How much weight should you lift to build muscle?
Enough that each set ends close to failure, wherever your reps land. The 2026 ACSM position stand found muscle grew similarly across loads from 30% to 100% of a max, and that ending sets with 2 to 3 reps in reserve is hard enough to drive gains. So the right weight is a matter of reps and effort: pick your reps with the sets and reps calculator, then use the weight that leaves about 2 in the tank.
For strength the weight matters more. The same position stand found strength rose with heavier loads, 80% of your max or more, which by the Epley formula is roughly a set of 6 or 7 with 2 left.
How much weight should a beginner lift?
Start at the bottom: the empty bar on barbell lifts, the lightest pin on a machine, the lightest pair of dumbbells. Do one set until about 2 reps feel left, and use that set to set the next. The ACSM recommends novices work with loads they could lift 8 to 12 times, which leaves room to learn the movement before going heavy.
If you're asking how much you should be able to lift for your bodyweight, that's a different number. The strength standards page compares your lifts with other lifters, and how strong am I scores them.
How the working weight is worked out
Your test set becomes an estimated one-rep max with the same formula the RIRLift app uses: Epley's, counting the reps you had left as reps you could have done. That max is worked back to the weight for your target reps at the reps in reserve RIRLift prescribes for that lift (2 on most compound lifts, 1 on isolation lifts and some heavy pulls), then rounded down to the load your equipment allows: 2.5 kg or 5 lb on a barbell, dumbbell or plate-loaded machine, 5 kg or 10 lb on a pin stack.
1RM = weight × (1 + (reps + RIR − 1) ÷ 30)
Working weight = 1RM ÷ (1 + (target reps + 2 − 1) ÷ 30)
60 × (1 + (8 + 2 − 1) ÷ 30) = 78 kg
78 ÷ (1 + (10 + 2 − 1) ÷ 30) = 57.07, shown as 57.5 kgMake it fit you
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Test with 10 or fewer reps
Pick a weight you'd fail with by about 10 reps. Longer sets say more about endurance than strength, and the estimate from them is rough.
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Too light or too heavy?
Five or more reps left means go up. Missing the bottom of your rep range, or changing your form to finish, means go down.
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Use small plates when you have them
With fractional plates, round the result down to the nearest 1 kg or 2.5 lb instead of the full step.
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Dumbbells are per hand
For dumbbell lifts, enter and read one dumbbell. The dumbbell weight calculator covers more dumbbell exercises.
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Re-test when it feels different
After a break, a new machine or a few sessions where the reps keep coming easier, run a fresh test set rather than adding weight blind.
Questions
How much weight should I lift to build muscle?
A weight that lets you finish your target reps with 1 to 3 left in the tank. Within that, light and heavy loads build similar muscle, so pick a rep range you can train well and match the weight to it.
How do I know if I'm lifting too heavy?
If you can't reach the bottom of your rep range, or your form changes to get the last reps, the weight is too heavy. Drop one step and build back up.
How much should I lift for my body weight?
That depends on the lift, your sex and your training age. The strength standards calculator compares your numbers with lifters at your bodyweight.
Do I need to test my one-rep max?
No. A hard set of 3 to 10 reps with your reps in reserve gives a usable estimate, and the one-rep max calculator shows it.
How often should I increase the weight?
When every set reaches the top of your rep range with about 2 reps left. When to increase weight covers the rest.
Should women lift lighter weights?
Women use the same rule: the weight that leaves about 2 reps in the tank at your target reps. The number differs from person to person, not the method.
Related calculators and templates
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What weight dumbbells should I use?
The same answer for nine common dumbbell exercises.
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Sets and reps chart
How many sets and reps to do with that weight.
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One-rep max calculator
Your estimated max from the same test set.
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Strength standards calculator
How your lifts compare at your bodyweight.
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How RIRLift picks your next weight
The same idea, run on every set you log.
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When to increase weight
The signals that mean go up, and by how much.
Sources
- Currier et al. (2026), ACSM position stand: resistance training prescription for muscle function, hypertrophy and physical performance
- American College of Sports Medicine (2009), position stand: progression models in resistance training for healthy adults
- Reynolds, Gordon and Robergs (2006), prediction of 1RM strength from multiple repetition maximum testing
- bStrong, how much weight to start with
Let the next weight pick itself
Log load, reps and RIR on every set and RIRLift works out each next weight from what you logged, rounded to your plates and machines; on a lift you have never done, it starts light and asks for one max-reps set.
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