531 Strength vs 1
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.
1
Easily calculate and track your one-rep max (1RM) for any lift. Estimate your maximum weight safely without testing, and monitor your progress over time with detailed charts. Improve your training with expert articles.
- Calculate 1RM and percentages
- Support for various lifts
- Track 1RM history with charts
- Add notes to calculations
- Access expert training articles
- Imperial/metric system support
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Whether you're a competitive lifter or just want to improve your strength and fitness, your one-rep max (1RM) is an essential tool. Calculate your max safely and easily, and then track it over time, on any lift with our easy-to-use calculator! In the simplest terms, your 1RM is the amount of weight you can lift for one rep on any given lift. In general, it’s good to know your max for key lifts like the squat, bench press, and deadlift, but your 1RM is critical even if you never plan to train that heavy. Many lifting programs are designed with a percent of your rep max in mind, and may call for something like using 65% of your 1RM for a given exercise. When you see that, you have to either test for your 1RM or estimate it. Testing your 1RM can be pretty intense, and it requires a high degree of caution to avoid injury. Fortunately, you can estimate your 1RM without testing it! Exercise scientists have devised a formula that's fairly accurate for most people, which is what powers this calculator. Our calculator makes it easy to calculate and track your 1RM and multiple percentages of it for every lift in the book! Features: · Calculate your 1RM and percentages · Choose from a variety of lifts (deadlift, bench press, squat, etc.), or add your own · Track and chart your 1RM history for each type of lift · Add notes each time you calculate your 1RM · Improve your weight training with articles by Bodybuilding.com experts · Choose imperial or metric system · Incredibly easy to use!
Screenshots
Verdict
531 Strength and 1 both sit at 4.9 stars, but that hides the real split: 94% of 531 Strength's written reviews are positive against 39% of 1's. 531 Strength also leads on price (Free vs $1.99) and ratings volume (12K vs 1.1K). 1's advantage is in-app purchases (none vs 4) and ads (none vs shown). On rating, update cadence and device support 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
531 Strength is free to download; 1 costs $1.99 up front. 531 Strength sells 4 one-off in-app purchases. 1 asks for nothing beyond the download.
On the App Store both sit at effectively the same score — 4.9 for 531 Strength against 4.8 for 1. That said, the two scores are not equally well evidenced: 531 Strength has 12K ratings behind it against 1.1K, 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 39% of 1's.
531 Strength ships an update every 2 months, 1 every 3 months. The most recent releases landed on November 1, 2026 and October 29, 2026 respectively.
| Parameter | 531 Strength | 1 |
|---|---|---|
| Price | Free — better | $1.99 |
| Rating | 4.9 (12K ratings) — better | 4.8 (1.1K ratings) |
| Positive reviews | 94.0% of reviews — better | 39.4% of reviews |
| Number of ratings | 12K — better | 1.1K |
| Update frequency | Every 2 months — better | Every 3 months |
| Ads | Yes | No — better |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 18.0 | 10.0 — better |
| Further details — not scored | ||
| Size | 26 MB | 47 MB |
| Age rating | 4+ | 9+ |
| Developer | Henrik Jachobsen | Bodybuilding.com |
Customer experience
531 Strength
1
User reviews
531 Strength
From 12K App Store ratingsWhat we love
- 🚀 Simple and efficient
- 👍 Intuitive interface
- 💪 Helps with strength gains
- 🔧 Customizable features
- ⏱️ Convenient timer
Room to improve
- 🔢 Inaccurate percentage calculations
- 🗓️ Lack of ability to plan future workouts
- 📋 Limited exercise tracking
- 💰 Paid features not worth the cost
1
From 1.1K App Store ratingsWhat we love
- 🚀 Great for calculating reps
- 👍 Good, simple app
- 👍 Quick easy to use tool
Room to improve
- 🐛 Numbers won't work
- 🐛 Single digit reps only
- 🐛 Links to articles not working
- 🐛 Keeps billing user
- 🐛 Inability to filter exercise history
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
1
Reported bugs
8 issues- Numbers won't work
- Single digit reps only
- Links to articles not working
- Keeps billing user
- Inability to filter exercise history
Show 3 moreShow fewer
- Cannot modify notes or dates
- Lack of decimal support
- Cannot upload old data
Requested features
11 requests- Show max weight for different rep ranges
- Option to count uneven weights
- Display percentages at all times
- Show percentile of max among lifters
- Allow selecting exercise to see PR chart
Show 6 moreShow fewer
- Ability to modify dates of lifts
- Add more weight increments
- Expand note functionality
- Add set tracking
- Allow decimal weight input
- Provide more detailed progress reporting
In-app purchases
531 Strength
- Additional exercises$1.99
- Adjustable set$1.99
- Plate calculator$1.99
Show 1 moreShow fewer
- Progress log$6.99
1
No in-app purchases









