531 Strength vs Rep Max Calculator
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
531 Strength
This app simplifies tracking your progress on the 5/3/1 strength training program. It calculates and displays weights, reps, and sets based on your one-rep max, allowing you to easily plan and execute your workouts. Rounding options help match available gym plates.
- Calculate 5/3/1 weights
- Track 1RM for exercises
- View cycle step weights
- Round weights to available plates
- Full overview of weights, reps, sets
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Makes it quick and easy to get a full overview of all weights, reps and sets based off your 1RM when you’re following the 5/3/1 program. - Save your current 1 RM for each of the four exercises - View calculated weights for each step in the cycle - Round the weight to match the plates you have available This app is made for people who are familiar with the structure of the 5/3/1 program and who needs simple access to the calculated weights for each exercise.
Rep Max Calculator
Calculate your maximum weight for a specific number of repetitions. Ideal for powerlifting, bodybuilding, and fitness enthusiasts, it supports calculations for 1 to 40 repetitions based on the weight lifted.
- Calculate 1-rep max
- Supports 1-40 repetitions
- Weight-based calculation
- Powerlifting, bodybuilding, fitness
- User-friendly interface
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Repeated maximum calculator. Repeated maximum (RM) is the maximum weight that can be lifted to a certain number of times. Calculation from 1 to 40 numbers of repeates by specified weight for powerlifting, bodybuilding and fitness.
Screenshots
Verdict
The clearest difference is ads: Rep Max Calculator at none against 531 Strength's shown. Rep Max Calculator also leads on iOS requirement (10.0 vs 18.0). 531 Strength's advantage is ratings volume (12K vs 3) and update cadence (every 2 months vs every 7 months). On price, rating, in-app purchases and monetization model there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. 531 Strength sells 4 one-off in-app purchases and Rep Max Calculator sells 3 in-app purchases, starting at $9.99 per month. Whichever you choose, the download price is not the number that matters.
On the App Store both sit at effectively the same score — 4.9 for 531 Strength against 5.0 for Rep Max Calculator. That said, the two scores are not equally well evidenced: 531 Strength has 12K ratings behind it against 3, so its average is the more settled of the two. Written reviews are what separate them: 94% of 531 Strength's written reviews are positive against 80% of Rep Max Calculator's.
531 Strength ships an update every 2 months, Rep Max Calculator every 7 months. The most recent releases landed on October 23, 2026 and September 30, 2026 respectively.
| Parameter | 531 Strength | Rep Max Calculator |
|---|---|---|
| Price | Free | Free |
| Rating | 4.9 (12K ratings) | 5.0 (3 ratings) — better |
| Positive reviews | 94.0% of reviews — better | 80.0% of reviews |
| Number of ratings | 12K — better | 3 |
| Update frequency | Every 2 months — better | Every 7 months |
| Ads | Yes | No — better |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 18.0 | 10.0 — better |
| Further details — not scored | ||
| Size | 26 MB | 28 MB |
| Age rating | 4+ | 4+ |
| Developer | Henrik Jachobsen | Roman Shimchenko |
Customer experience
531 Strength
Rep Max Calculator
Bugs and requests
531 Strength
Reported bugs
2 issues- Rest timer stops when app is backgrounded
- Plate calculator not flexible enough
Requested features
4 requests- Ability to adjust training max separately from 1RM
- Option to track rep PRs and estimated 1RM
- Accessory exercise tracking and planning
- Sync progress across devices
Rep Max Calculator
Not enough reviews yet to summarise bugs or requests.
In-app purchases
531 Strength
- Additional exercises$1.99
- Adjustable set$1.99
- Plate calculator$1.99
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- Progress log$6.99
Rep Max Calculator
- Monthly subscription$9.991 Month
- Subscription for year$99.991 Year
- Save Settings$1.99
Questions
Is 531 Strength free?
Is Rep Max Calculator free?
Which has better reviews, 531 Strength or Rep Max Calculator?
Do 531 Strength or Rep Max Calculator have ads?
Which is updated more often, 531 Strength or Rep Max Calculator?
Other comparisons
