Deadlift 1RM Calculator

Your deadlift one-rep max is the heaviest weight you can pull from the floor to a full standing lockout for one rep. This calculator estimates it from a heavy low-rep set, running the weight and reps through four established formulas (Epley, Brzycki, Lombardi, O'Conner) and averaging them. For the deadlift more than any other lift, you should estimate from very low reps — and this page explains exactly why.

Why Deadlift Estimates Use Lower Reps

The deadlift is the most fatiguing lift in the gym, and that breaks rep-based prediction in two ways:

• Systemic fatigue: A heavy deadlift loads nearly every muscle and hammers the central nervous system. Each rep in a set degrades the next far more than in a bench or curl, so a 10-rep deadlift set is disproportionately harder than the formulas assume — they will under-predict if you grind, or the set simply ends early.
• Form breakdown: As fatigue builds, the lower back rounds and the bar drifts forward. Reps done with degraded technique aren't comparable to a clean max, so they corrupt the estimate.

For these reasons, estimate your deadlift from a heavy double or triple. Avoid touch-and-go reps for estimation — reset and brace each rep from a dead stop so every rep starts from the same position.

The Formulas

Worked Example: A Heavy Double

You deadlift 180 kg for 2 reps:

• Epley: 180 × (1 + 2/30) = 192.0 kg
• Brzycki: 180 × 36/35 = 185.1 kg
• Lombardi: 180 × 2^0.10 = 192.9 kg
• O'Conner: 180 × (1 + 2/40) = 189.0 kg

Average ≈ 189.8 kg estimated deadlift 1RM. Because deadlift singles often exceed what doubles predict, this is a conservative, trustworthy figure.

Deadlift Training Percentages

Note that deadlift rep counts at a given percentage are usually lower than for the squat or bench — most lifters can't match the rep numbers in a generic chart because of how fatiguing each pull is. Adjust downward by a rep or two.

Grip and CNS Notes

• Grip can cap your reps before your back and legs are done. If the bar slips, that's a grip failure, not a true strength limit — consider a mixed grip or straps for estimation sets (note that straps inflate the number versus a competition pull).
• CNS cost is high. Don't test a deadlift max more than once every 6–10 weeks; heavy pulls leave residual fatigue that suppresses performance for days.
• Reset between reps for estimation. Touch-and-go reps bounce off the floor and over-predict your true dead-stop max.

Note: This estimate is for training and informational use only. The deadlift loads the spine heavily — keep a neutral back, warm up progressively, and consult a qualified coach or healthcare professional before attempting maximal pulls.