Comparison

531 Strength vs 1

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

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.

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
Read full description

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.

About

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.

Highlights
  • 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
Features
Read full description

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

531 Strength4 screens
14 screens

Verdict

The call

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

CostPrice · In-app purchases · Ads · Monetization

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.

ReceptionRating · Positive reviews · Number of ratings

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.

UpkeepUpdate frequency

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.

Scorecard7 real differences · 3 level
531 Strength versus 1: the parameters behind the verdict, then further details
Parameter531 Strength1
PriceFree — better$1.99
Rating4.9 (12K ratings) — better4.8 (1.1K ratings)
Positive reviews94.0% of reviews — better39.4% of reviews
Number of ratings12K — better1.1K
Update frequencyEvery 2 months — betterEvery 3 months
AdsYesNo — better
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS18.010.0 — better
Further details — not scored
Size26 MB47 MB
Age rating4+9+
DeveloperHenrik JachobsenBodybuilding.com

Customer experience

531 Strength

All ratings11,645 ratings
Positive98.0%
Neutral1.2%
Negative0.8%
Written reviews282 reviews
Positive94.0%
Neutral2.8%
Negative3.2%

1

All ratings1,056 ratings
Positive95.5%
Neutral2.7%
Negative1.9%
Written reviews33 reviews
Positive39.4%
Neutral18.2%
Negative42.4%

User reviews

531 Strength

From 12K App Store ratings

What 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 ratings

What 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 more
  • 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 more
  • 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

4 purchases

531 Strength

One-time4
  • Additional exercises$1.99
  • Adjustable set$1.99
  • Plate calculator$1.99
Show 1 more
  • Progress log$6.99
None

1

No in-app purchases

Questions

Is 531 Strength free?
531 Strength is free to download, with in-app purchases available.
Is 1 free?
1 costs $1.99, with no in-app purchases.
Which has better reviews, 531 Strength or 1?
531 Strength is rated higher. 531 Strength averages 4.9 out of 5 from 12K ratings, while 1 averages 4.8 from 1.1K ratings.
Do 531 Strength or 1 have ads?
531 Strength shows ads; 1 does not.
Which is updated more often, 531 Strength or 1?
531 Strength ships an update every 2 months, and 1 every 3 months. Most recently, 531 Strength was updated on November 1, 2026 and 1 on October 29, 2026.

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