Comparison

531 Strength vs 1RM Calculator

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

1RM Calculator

Easily calculate your one-rep max (1RM) strength with this app. It supports RPE input and allows you to estimate rep maxes based on your 1RM. Track your progress by saving your 1RM history for different exercises.

Highlights
  • 1RM calculation with RPE
  • Rep max estimation
  • Save 1RM history
  • Customizable exercises
  • Dark theme
Features
Read full description

Estimate your one rep max (1RM) from any set. Enter the weight and reps you lifted, add RPE if you track it, and get your estimated max in seconds. FEATURES - 1RM calculator with optional RPE: reps left in the tank are counted, so 10 reps at RPE 7 is treated like a 13-rep max - Transparent formulas: your estimate is the average of Epley, Brzycki (up to 12 reps), Wathan, and Mayhew - Estimated rep maxes from 2 to 12 reps, each shown as a percentage of your 1RM, for planning working sets - Save results to your history by exercise, including your own custom exercises - Edit or backdate saved records - Export your history as CSV - kg or lbs, light or dark theme - 9 languages - No account needed: your records stay on your device PRO - 1RM progress chart for each exercise - Rep max table with your best recorded set for each rep count - No ads Pro is available as a monthly or yearly subscription, or as a one-time lifetime purchase. Subscriptions renew automatically until canceled in your store account settings. Your 1RM is an estimate, not a tested max. Estimates are most reliable at lower reps. Terms: https://1rm.workoutwise.app/legal/terms/ Privacy Policy: https://1rm.workoutwise.app/legal/privacy-policy/

Screenshots

531 Strength4 screens
1RM Calculator4 screens

Verdict

The call

The clearest difference is ads: 1RM Calculator at none against 531 Strength's shown. 1RM Calculator also leads on iOS requirement (15.0 vs 18.0). 531 Strength's advantage is ratings volume (12K vs 130) and update cadence (every 2 months vs every 4 months). On price, rating, review sentiment and in-app purchases 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

Both are free to download. 531 Strength sells 4 one-off in-app purchases and 1RM Calculator sells 3 in-app purchases, starting at $1.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.9 for 531 Strength against 4.9 for 1RM Calculator. That said, the two scores are not equally well evidenced: 531 Strength has 12K ratings behind it against 130, 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 100% of 1RM Calculator's.

UpkeepUpdate frequency

531 Strength ships an update every 2 months, 1RM Calculator every 4 months. Both last shipped on November 7, 2026.

Scorecard4 real differences · 6 level
531 Strength versus 1RM Calculator: the parameters behind the verdict, then further details
Parameter531 Strength1RM Calculator
PriceFreeFree
Rating4.9 (12K ratings) — better4.9 (130 ratings)
Positive reviews94.0% of reviews100.0% of reviews — better
Number of ratings12K — better130
Update frequencyEvery 2 months — betterEvery 4 months
AdsYesNo — better
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS18.015.0 — better
Further details — not scored
Size26 MB28 MB
Age rating4+4+
DeveloperHenrik JachobsenYuri Koshiishi

Customer experience

531 Strength

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

1RM Calculator

All ratings116 ratings
Positive99.1%
Neutral0.0%
Negative0.9%
Written reviews18 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

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

1RM Calculator

Not enough reviews yet to summarise bugs or requests.

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
3 purchases

1RM Calculator

Subscriptions2
  • 1 Rep Max Pro Monthly$1.991 Month
  • 1 Rep Max Pro Annual$9.991 Year
One-time1
  • 1 Rep Max Pro Lifetime$29.99

Questions

Is 531 Strength free?
531 Strength is free to download, with in-app purchases available.
Is 1RM Calculator free?
1RM Calculator is free to download, with in-app purchases available.
Which has better reviews, 531 Strength or 1RM Calculator?
531 Strength is rated higher. 531 Strength averages 4.9 out of 5 from 12K ratings, while 1RM Calculator averages 4.9 from 130 ratings.
Do 531 Strength or 1RM Calculator have ads?
531 Strength shows ads; 1RM Calculator does not.
Which is updated more often, 531 Strength or 1RM Calculator?
531 Strength ships an update every 2 months, and 1RM Calculator every 4 months. Most recently, 531 Strength was updated on November 7, 2026 and 1RM Calculator on November 7, 2026.

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