# 531 Strength vs Rep Max Calculator

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.

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.

## The numbers

| Metric | 531 Strength | Rep Max Calculator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.9 (12K ratings)](https://appshunter.io/ios/app/531-strength/id1062989244/reviews) | **[5.0 (3 ratings)](https://appshunter.io/ios/app/rep-max-calculator/id1103321723/reviews)** |
| Number of ratings | **12K** | 3 |
| Positive reviews | **94.0% of reviews** | 80.0% of reviews |
| In-app purchases | Yes | Yes |
| Ads | Yes | **No** |
| Update frequency | **Every 2 months** | Every 7 months |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 26 MB | 28 MB |
| Requires iOS | 18.0 | **10.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Henrik Jachobsen](https://appshunter.io/developer/497731838) | [Roman Shimchenko](https://appshunter.io/developer/916564826) |

## What reviewers say

### 531 Strength

[App page](https://appshunter.io/ios/app/531-strength/id1062989244)

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.

**Highlights:** Calculate 5/3/1 weights, Track 1RM for exercises, View cycle step weights, Round weights to available plates, Full overview of weights, reps, sets

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Additional exercises | $1.99 | one-time |
| Adjustable set | $1.99 | one-time |
| Plate calculator | $1.99 | one-time |
| Progress log | $6.99 | one-time |

**What reviewers like**

- 🚀 Simple and efficient
- 👍 Intuitive interface
- 💪 Helps with strength gains
- 🔧 Customizable features
- ⏱️ Convenient timer

**What reviewers complain about**

- 🔢 Inaccurate percentage calculations
- 🗓️ Lack of ability to plan future workouts
- 📋 Limited exercise tracking
- 💰 Paid features not worth the cost

**Reported bugs**

- Rest timer stops when app is backgrounded
- Plate calculator not flexible enough

**Requested features**

- 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

[App page](https://appshunter.io/ios/app/rep-max-calculator/id1103321723)

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.

**Highlights:** Calculate 1-rep max, Supports 1-40 repetitions, Weight-based calculation, Powerlifting, bodybuilding, fitness, User-friendly interface

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly subscription | $9.99 | per month |
| Subscription for year | $99.99 | per year |
| Save Settings | $1.99 | one-time |


## Frequently asked questions

### Is 531 Strength free?

531 Strength is free to download, with in-app purchases available.

### Is Rep Max Calculator free?

Rep Max Calculator is free to download, with in-app purchases available.

### Which has better reviews, 531 Strength or Rep Max Calculator?

Rep Max Calculator is rated higher. 531 Strength averages 4.9 out of 5 from 12K ratings, while Rep Max Calculator averages 5.0 from 3 ratings.

### Do 531 Strength or Rep Max Calculator have ads?

531 Strength shows ads; Rep Max Calculator does not.

### Which is updated more often, 531 Strength or Rep Max Calculator?

531 Strength ships an update every 2 months, and Rep Max Calculator every 7 months. Most recently, 531 Strength was updated on October 23, 2026 and Rep Max Calculator on September 30, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*