How much weight should I add per week?

For compounds (bench, squat), 1-2.5kg per week is realistic. For isolation (curls, lateral raises), 0.5-1kg. This calculator considers your current e1RM and calculates the optimal increase.

What if I can't increase the weight?

Then increase reps at the same weight, or lower your RIR. All three methods produce progressive overload. What matters is that your e1RM rises over time, not necessarily the weight on the bar.

Progressive Overload Calculator: What Should You Lift Next?

Interactive Tool · Based on Epley (1985) + Auto-Regulation (Zourdos 2023)

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.

How it works: Pick an exercise from your last session and enter your heaviest working set: weight, reps and your RIR, meaning how many more reps you could have done. Below that, choose how many reps you want to hit next time and with how much in reserve. The calculator estimates your max (e1RM) and suggests the weight for your next session.

YOUR LAST PERFORMANCE

Weight last session (kg/lbs)

Reps completed

RIR (Reps in Reserve)

YOUR NEXT SESSION

Target reps

Target RIR

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Recommended weight for your next session

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Your e1RM

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Change

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% of 1RM

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.

Key insight: Progressive overload doesn't mean adding weight every week. It means your e1RM rises over weeks and months. Sometimes you progress through more reps, sometimes through better technique (lower RIR), and sometimes through more weight. This calculator accounts for all three factors.

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 higher. 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.

The research says: Training at RIR 1-3 builds practically the same muscle as training to failure (RIR 0), with less fatigue (Refalo et al. 2023, 2024). Zourdos et al. (2023) confirmed that RIR-based auto-regulation is the most effective method for managing training intensity.

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?

This happens when you increase your target reps or lower your target RIR. Example: 80kg × 6 @ RIR 2 has an e1RM of ~98kg. If you now want 10 reps @ RIR 2, you need ~73kg: less weight but the same relative intensity. Your e1RM stays the same; you're just training in a different rep range.

Should I use the same weight for every set?

Yes, for most hypertrophy programs, "straight sets" (same weight, same reps, all sets) are most effective. This calculator gives you the weight for this standard approach. MUSCLE TECHNICS automatically adjusts weights if your RIR during training is higher or lower than planned.

More weight or more reps: which is better?

Both create progressive overload. The meta-analysis (Schoenfeld 2017) shows hypertrophy is equally effective across a broad load range, as long as intensity is sufficient (RIR 0-3). For beginners, more weight at the same reps is simplest. For advanced lifters, switching to more reps (same RIR) can provide new growth stimulus.

How often should I increase?

Try to progress every session, whether through more weight, more reps, or lower RIR. If an exercise sets no new best for 4 weeks, it has stalled. Then adjust training volume or exercise selection. The app checks this per exercise, first tries an increase and only swaps the exercise for one with the same movement pattern if that brings nothing.

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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