RPE Weight Calculator

Dial in your working weight for any target reps and effort level. Enter your one rep max, pick how many reps you want to hit and how hard it should feel — Adiletix tells you exactly what to load on the bar.

1RM (kg)

How many reps?

Rate of Perceived Exertion90

Hard — 1 rep left in reserve

Lift this

64kg

≈ 80% of your 1RM · 5 reps @ RPE 90

Estimates are a starting point — adjust to how the bar actually moves on the day. Not medical advice.

Get auto-calculated working weights inside every workout with the Adiletix app.

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How the RPE calculator works

The calculator scales your one rep max by the effort you choose, then adjusts for how many reps you are aiming to hit:

weight = 1RM × (RPE / 100) × (1.0278 − 0.0278 × reps)

At a single rep the rep factor is 1.0, so the result is your effective max for that effort. Every additional rep takes roughly 2.78% off the bar. This is the same formula the Adiletix app uses to prescribe set weights, so what you see here matches what you will be handed in a session.

What each RPE means

RPE	How it feels	Reps in reserve
100	Maximal effort	No reps left in the tank
90–99	Hard	1 rep left in reserve
80–89	Challenging	2–3 reps in reserve
70–79	Moderate	3–4 reps in reserve
50–69	Light	Building or recovering

Frequently asked questions

What is RPE in weightlifting?: RPE stands for rate of perceived exertion — how hard a set felt. It lets a program prescribe effort rather than a fixed number, so the weight adapts to how strong you are on the day rather than to a number written weeks ago.
How does this RPE calculator work?: It scales your one rep max by the effort you pick, then adjusts for the number of reps: working weight = 1RM x (RPE / 100) x (1.0278 - 0.0278 x reps). At one rep the rep factor is 1.0, and each extra rep takes roughly 2.78% off the load.
Why is the RPE scale 50 to 100 instead of 1 to 10?: Adiletix uses effort as a percentage so it maps directly onto your one rep max, and it matches the scale in the app. As a rough translation, RPE 9 on the classic 10-point scale is 90 here, RPE 8 is 80, and so on.
What RPE should I train at?: Most working sets for strength sit between 70 and 90 — hard enough to drive progress with a rep or three still in reserve. Efforts at 95 and above are best saved for testing or a peaking block, since they are slow to recover from.
How accurate is an RPE calculator?: It is a starting point, not a prescription. Rep-max formulas lose accuracy above roughly five reps, and sleep, stress and fatigue all move the number on the day. Load the suggested weight, judge the first set, and adjust from there.
Do I need my one rep max to use it?: You need an estimate. If you have never tested a true 1RM, use the heaviest single you are confident you could hit today — the result scales proportionally, so a close estimate gives a usable working weight.

Know the weight and need to know which plates to load? Open the barbell plate calculator.

Estimates are a starting point, not medical or coaching advice. Adjust to how the bar actually moves on the day.

How the RPE calculator works

The calculator scales your one rep max by the effort you choose, then adjusts for how many reps you are aiming to hit:

weight = 1RM × (RPE / 100) × (1.0278 − 0.0278 × reps)

RPE

How it feels

Reps in reserve

100

Maximal effort

No reps left in the tank

90–99

Hard

1 rep left in reserve

80–89

Challenging

2–3 reps in reserve

70–79

Moderate

3–4 reps in reserve

50–69

Light

Building or recovering

Frequently asked questions

What is RPE in weightlifting?

RPE stands for rate of perceived exertion — how hard a set felt. It lets a program prescribe effort rather than a fixed number, so the weight adapts to how strong you are on the day rather than to a number written weeks ago.

How does this RPE calculator work?

It scales your one rep max by the effort you pick, then adjusts for the number of reps: working weight = 1RM x (RPE / 100) x (1.0278 - 0.0278 x reps). At one rep the rep factor is 1.0, and each extra rep takes roughly 2.78% off the load.

Why is the RPE scale 50 to 100 instead of 1 to 10?

Adiletix uses effort as a percentage so it maps directly onto your one rep max, and it matches the scale in the app. As a rough translation, RPE 9 on the classic 10-point scale is 90 here, RPE 8 is 80, and so on.

What RPE should I train at?

Most working sets for strength sit between 70 and 90 — hard enough to drive progress with a rep or three still in reserve. Efforts at 95 and above are best saved for testing or a peaking block, since they are slow to recover from.

How accurate is an RPE calculator?

It is a starting point, not a prescription. Rep-max formulas lose accuracy above roughly five reps, and sleep, stress and fatigue all move the number on the day. Load the suggested weight, judge the first set, and adjust from there.

Do I need my one rep max to use it?

You need an estimate. If you have never tested a true 1RM, use the heaviest single you are confident you could hit today — the result scales proportionally, so a close estimate gives a usable working weight.

Know the weight and need to know which plates to load? Open the barbell plate calculator.

Estimates are a starting point, not medical or coaching advice. Adjust to how the bar actually moves on the day.