Deadlift One Rep Max Calculator

Enter Deadlift Session Details

Lifted Weight

Repetitions Completed

Unit

Body Weight (Optional)

Set Effort RPE

Rounding Increment

Custom Training Percentage

Example Data Table

Lifter	Weight	Reps	RPE	Average 1RM Estimate
Example A	160 kg	5	9	188.5 kg
Example B	315 lb	3	10	343.6 lb
Example C	140 kg	8	8.5	183.2 kg

Formula Used

This calculator estimates deadlift one rep max with several proven equations. It then averages the valid outputs to reduce dependence on one formula alone.

Epley: 1RM = weight × (1 + reps ÷ 30)

Brzycki: 1RM = weight × 36 ÷ (37 − reps)

Lombardi: 1RM = weight × reps^0.10

O'Conner: 1RM = weight × (1 + reps ÷ 40)

Mayhew: 1RM = weight × 100 ÷ (52.2 + 41.9 × e^{−0.055×reps})

Wathan: 1RM = weight × 100 ÷ (48.8 + 53.8 × e^{−0.075×reps})

McGlothin: 1RM = weight × 100 ÷ (101.3 − 2.67123 × reps)

If RPE is below 10, the calculator estimates repetitions in reserve and adds them to performed reps. Effective reps = completed reps + (10 − RPE).

Training loads, suggested attempts, and warm-up values are based on the average estimate. Rounded outputs follow your selected plate increment.

How to Use This Calculator

Enter the weight used in your deadlift set.
Add the number of repetitions completed with solid form.
Choose kilograms or pounds.
Enter body weight if you want relative strength shown.
Add RPE to account for repetitions left in reserve.
Select a rounding increment that matches your gym plates.
Set a custom percentage for a target training load.
Press the calculate button to display the result above the form.
Review formula spread, attempt suggestions, warm-ups, and charted percentages.
Use the CSV or PDF buttons to export your results.

Frequently Asked Questions

1. Is a deadlift 1RM estimate always exact?

No. It is an informed estimate based on equations and your set performance. Sleep, fatigue, technique, grip, and motivation can change what you lift on a true max day.

2. Which rep range gives the best estimate?

Most formulas work best with challenging sets between 1 and 10 reps. Accuracy usually drops when sets get very high, especially if technique changes late in the set.

3. Why does the calculator use several formulas?

Different equations react differently to rep count. Showing several values lets you compare the spread and use the average for more balanced planning.

4. What does RPE change here?

RPE adjusts the effective rep count. A set at RPE 8 suggests about two reps left in reserve, so the estimate rises compared with the same set taken to failure.

5. Should I use average 1RM or the highest formula?

Use the average for routine programming. Use the upper end only when you know the set quality was strong, your technique was consistent, and recovery is excellent.

6. Can this help choose meet attempts?

Yes. The opener, second, and third suggestions provide a simple planning baseline. Adjust them for meet conditions, equipment rules, and how your warm-ups feel that day.

7. Why include body weight?

Body weight lets the calculator show relative strength. That makes it easier to compare progress across weight changes or evaluate strength-to-size efficiency.

8. Can I use this for rack pulls or Romanian deadlifts?

You can, but results are most meaningful for conventional or sumo deadlift sets. Variations often have different mechanics and may not reflect your full-range competition pull.