Progressive Overload Calculator — What Should You Lift Next?
You trained last week. But what do you put on the bar this week? This calculator estimates your 1RM from your last performance and tells you the optimal weight for your next session — adjusted for your target reps and target RIR.
YOUR LAST PERFORMANCE
YOUR NEXT SESSION
What Is Progressive Overload?
Progressive overload is the fundamental principle behind muscle growth. It states: your muscles only grow when exposed to a greater stimulus than last time. Without progressive overload, there is no adaptation — no matter how often you train.
The stimulus can increase in three ways:
- More weight at the same reps and RIR
- More reps at the same weight and RIR
- Lower RIR at the same weight and reps
All three increase your e1RM (estimated one-rep max) — and that's the true measure of progress.
How the Calculator Works
The calculator uses the Epley formula (1985) — the same formula MUSCLE TECHNICS uses internally:
e1RM = Weight × (1 + (Reps + RIR) / 30)
By factoring in RIR, your e1RM reflects your true capacity — not just what you actually lifted, but what you could have lifted. This is the foundation for precise weight recommendations.
From your e1RM, the calculator works backwards: what weight do you need to hit your target reps at your target RIR?
When to Increase — and When Not To
Increase the weight when you hit your target reps at RIR 2 or lower. This means you have room to progress.
Keep the weight when you barely hit your target reps at RIR 0-1. You're at your limit — increasing would compromise form.
Reduce the weight when you couldn't complete your target reps, or when returning from a break (deload, illness).
Realistic Progression Rates
- Beginners (0-1 year): +2-5kg/week on compounds, +1-2kg on isolation
- Intermediate (1-3 years): +1-2.5kg/week on compounds, +0.5-1kg on isolation
- Advanced (3+ years): +0.5-1kg/week on compounds, +0.5kg or more reps on isolation
Frequently Asked Questions
What if the calculator suggests less weight than last week?
Should I use the same weight for every set?
More weight or more reps — which is better?
How often should I increase?
Automatic Progressive Overload
MUSCLE TECHNICS calculates your optimal weight for every set automatically — based on your e1RM, RIR, and the science-backed rep range. No manual calculations needed.
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