One rep max calculator
Estimate 1RM and prepare loads from 60% to 95%.
NALKO Free strength tools
Free strength calculators for planning and measuring
Estimate a one-rep max, turn RPE into a load, calculate FFMI or find the plates for your barbell. Treat every output as a starting point to verify in training.
Free, no credit card
4
tools available
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Services
Available strength calculators
Choose the tool that answers today’s decision without mistaking an estimate for guaranteed performance.
FFMI calculator
Relate estimated fat-free mass to height without treating it as measured muscle.
- Raw and normalized FFMI
- No “natty” label
RPE/RIR calculator
Turn an RPE-rated set into an estimated one-rep max and target loads.
- RPE linked to RIR
- An inspectable formula
Barbell plate calculator
Find the plates to place on each side of a barbell in kg or lb.
- Your actual equipment
- No hidden overshoot
Worked examples
Four calculations for four different decisions
These examples show what the tools produce. They do not replace a technically sound set or consistent tracking.
Estimate a load
The 1RM and RPE tools turn a submaximal set into load references while keeping uncertainty visible.
Load the barbell
The plate calculator finds the closest reachable combination without exceeding your target load.
Describe fat-free mass
FFMI relates estimated fat-free mass to height without claiming to measure muscle alone or prove “natural” status.
Why these tools are different
Why these tools are different
One intent per calculator
1RM, RPE, FFMI and barbell loading each keep a distinct page and output.
Visible assumptions
Formula, units, rounding and limitations remain available before any optional save.
A route into the training log
Estimates become useful when compared with loads, reps and RIR actually logged over time.
From search to a useful action
From search to a useful action
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Choose the decision
Pick the calculator that matches your set, body-composition input or barbell.
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Read the limitations
Check the formula and the conditions that make the result more or less reliable.
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Test progressively
Use the result as a starting point, then adjust from technique and real training feedback.
FAQ
Frequently asked questions
Which strength calculators are free?
The 1RM, RPE/RIR, FFMI and barbell plate calculators show their complete results without an account. Sign-in is only for saving.
Which calculator should I use to select a load?
Use 1RM from a set close to failure, or RPE when you also estimated reps in reserve. Then use the plate calculator to build the barbell.
Do these calculators replace training records?
No. A formula simplifies one decision; only comparable, well-executed sets repeated over time show a useful progression.