Training tool

E1RM calculator

Estimate a practical one-rep max from a working set so you can judge progress and choose better training loads.

Best for

Lifters tracking strength without maxing out every week

Use it to

Estimate 1RM from a set you actually performed

Output

A usable estimated max plus quick training-load targets

Example output

Sample estimate from a normal work set

This page shows a fixed example so you can understand the output shape. The full editable calculator stays inside the app.

100 × 5 @ 8

123.3

70%: 86
75%: 92
80%: 99
85%: 105

Methodology

How this page was put together

These pages are reviewed against IronFlow's current public program library, released app capabilities, and public training references.

Updated

June 30, 2026

Built from

IronFlow's current program library, import flows, released calculators, and app capabilities as of June 30, 2026.

Use this page for

Quick reference and example outputs when you want to understand the calculation before using it in your training flow.

Note

This public page is content-only. The editable calculator stays inside IronFlow.

Why use an E1RM instead of a true max every session?

Track progress from normal training

You can estimate strength from a working set instead of testing a true 1RM every time.

Make load decisions faster

A rough estimated max gives you a better anchor for top sets, backoff work, and weekly adjustments.

Keep fatigue lower

Using submaximal sets to estimate performance is usually easier to recover from than frequent max attempts.

E1RM calculator FAQ

What is E1RM?

E1RM means estimated one-rep max. It uses a completed set to approximate what you could likely lift for a single rep.

Why include RPE?

RPE helps adjust the estimate based on how close the set was to failure, which makes the result more useful than reps alone.

Should I replace true max testing completely?

No. E1RM is best for regular monitoring, while true max tests are still useful occasionally when your program calls for them.

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