RIR ↔ %1RM Calculator
Two-way converter between reps in reserve (RIR), reps performed, and percentage of 1RM. Built on the Mike Tuchscherer / RTS RIR-to-%1RM table — the standard for autoregulated programming.
Set details
What is RIR?
RIR (Reps in Reserve) is how many more reps you could have done with good form before missing. RIR 2 means you stopped with 2 reps left in the tank. It's the inverse of RPE — RIR 2 ≈ RPE 8.
RIR-to-%1RM table (Tuchscherer/RTS)
For each rep number, %1RM drops by ~3% for each additional RIR. Example: a 5-rep set @ RIR 0 ≈ 87% 1RM; @ RIR 2 ≈ 81% 1RM.
Why use RIR?
- Autoregulates load — bad day, lighter weight, same RIR
- Caps fatigue — RIR 1–3 hits stimulus without grinding
- Easier to learn than RPE for beginners
FAQ
What's the right RIR for hypertrophy?
RIR 0–3 all build muscle if volume is matched. RIR 1–2 is the sweet spot for most hypertrophy programs — high enough effort, low enough fatigue.
For strength?
RIR 0–1 on top sets, RIR 2–4 on backoff sets. Heavy doubles and triples at RIR 0–1 build the SBD lifts.
How accurate is RIR?
Trained lifters are accurate within 1 rep about 70% of the time. Beginners overestimate effort — they say RIR 0 when they had 3–4 left.
Auto-regulate every set.
FitBear asks for your RIR after each set and adjusts the next one in real time.
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