| Lift | Weight | Reps | Estimated 1RM | Training Max (90%) |
|---|---|---|---|---|
| Bench Press | 100 kg | 5 | 116.7 kg | 105.0 kg |
| Back Squat | 140 kg | 3 | 154.0 kg | 138.6 kg |
| Deadlift | 180 kg | 2 | 192.0 kg | 172.8 kg |
| Overhead Press | 60 kg | 6 | 72.0 kg | 64.8 kg |
The Epley estimate is commonly written as: 1RM = Weight × (1 + Reps ÷ 30).
- Weight is the load you lifted for a completed set.
- Reps is the number of repetitions completed.
- RIR (optional) is added to reps as an effort estimate: effective reps = reps + RIR.
- Training max is calculated as a chosen percentage of the estimated 1RM.
- Rounding is applied using your increment and mode (nearest, up, or down).
- Complete a safe set of 1–10 reps with good form.
- Enter the weight and reps. Add RIR only if you track it.
- Choose units and a rounding increment that matches your plates.
- Set a training max percent to plan submaximal work.
- Press Submit to view your estimated 1RM and planning tables.
- Use CSV for logging and PDF for sharing or printing.
Estimated Max Reliability
The Epley relationship scales load by 1 + reps/30, so higher rep sets inflate the estimate. Five reps imply a 1.1667 multiplier, while ten reps imply 1.3333. Accuracy is usually best when the set is hard but technically clean, typically 1–8 reps, because fatigue and pacing distort bar speed at high reps. For endurance‑biased athletes, estimates from 12+ reps can overshoot by 5–15%.
Using Reps in Reserve
Adding reps in reserve converts an easier set into an effort‑matched estimate. If you lifted 100 kg for 5 reps with 2 RIR, effective reps become 7 and the multiplier becomes 1.2333, giving an estimated 123.3 kg. Keep RIR conservative; over‑optimistic RIR is a common cause of inflated targets. Track RIR with the same scale each session, and avoid mixing “grindy” reps with casual counting.
Training Max for Programming
A training max is a planning anchor, not a true limit. Many strength templates set training max at 85–95% of the estimate to keep volume productive and reduce missed lifts. If your estimated 1RM is 160 kg, 90% yields 144 kg, making 70–85% work sets land in a sustainable range. Re‑test every 4–8 weeks, and lower the training max after illness, travel, or poor sleep streaks.
Rounding and Loadability
Gym plates and dumbbell jumps rarely match exact calculations. Rounding to 2.5 kg or 5 lb mirrors standard loading and improves adherence. Rounding up is conservative for single attempts, while rounding down is safer for volume blocks. Consistent rounding also makes progress tracking clearer across weeks. If your gym uses micro‑plates, a 1.0 or 0.5 increment can reduce large jumps on pressing movements.
Interpreting the Tables
The warm‑up table expresses percentages of your training max, which is useful for ramp sets and readiness checks. The rep table inverts the formula to suggest approximate working weights for 1–12 reps. Use it to set starting loads, then adjust based on form, bar speed, and recovery. Compare trends across lifts: squats often tolerate higher percentages than presses, and deadlifts may require more conservative volume. Log each session to reveal steady strength momentum.
What does the calculator estimate?
It estimates your one‑rep max from a completed set using the Epley relationship, then derives an optional training max and planning tables for common percentages and rep targets.
Which rep range is best for accuracy?
Estimates are usually most reliable with hard sets of 1–8 reps. Higher‑rep sets increase fatigue and technique drift, which can inflate the predicted max even when the formula is mathematically correct.
How should I use reps in reserve?
If you stop with reps left, add a cautious RIR value to approximate effort. For example, 5 reps with 2 RIR is treated like 7 effective reps. Avoid guessing big RIR numbers on fast days.
How do I choose a training max percentage?
Many athletes start with 90% for balanced strength and volume. If you miss reps or recover slowly, try 85–88%. If you are peaking for heavy singles and feel fresh, 92–95% can work briefly.
Why does rounding matter?
Real plates come in fixed jumps. Rounding to 2.5 kg or 5 lb makes the output loadable and repeatable. Use rounding down for volume blocks and rounding up when planning cautious single attempts.
Can I use it for dumbbells or machines?
Yes, as long as the movement allows consistent full‑range reps. Estimates can vary more with machines, straps, or spotter assistance. Treat the number as a trend indicator and compare it only within the same exercise.