Comparison

One Rep Max vs 531 Strength

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

Head to head
About

One Rep Max

Safely estimate your maximum lift potential for various strength exercises using scientific formulas. Track your progress visually, set goals, and fine-tune estimates with perceived exertion. Ideal for powerlifters, CrossFit athletes, and strength enthusiasts.

Highlights
  • Precise 1RM calculations with 7 scientific formulas
  • RPE integration for fine-tuned estimates
  • Custom exercise tracking for any lift
  • Visual progress graphs
  • Percentage charts for training
  • Goal setting and progress monitoring
Features
Read full description

Stronger Training, Smarter Progress One Rep Max helps you safely and accurately determine your maximum lift potential for bench press, deadlift, squat, and any other strength exercise - without risking injury. Key Features: • Precise Calculations - 7 scientific formulas for accurate strength predictions: Epley, Brzycki, Lombardi, Mayhew, McGlothin, O'Conner, Wathan • RPE Integration - Factor in Rate of Perceived Exertion to fine-tune your max estimates based on how difficult sets feel • Custom Exercise Tracking - Create and monitor any lift that matters to you • Visual Progress - Beautiful graphs show your strength journey over time • Percentage Charts - Quick reference guide for training percentages • Goal Setting - Set targets and track your path to reaching them Perfect for: • Powerlifters optimizing their training cycles • CrossFit athletes tracking multiple movement patterns • Olympic weightlifters monitoring progress • Strength enthusiasts at any level Advanced Features: • Choose between multiple calculation formulas for different lift types • Track unlimited exercises with custom notes • Rate of Perceived Exertion (RPE) - Fine-tune your 1RM estimates based on how difficult sets feel • Analyze detailed statistics including volume and frequency • Set and monitor progress toward specific strength goals The Science Behind The Numbers: Our app employs multiple validated formulas to estimate your one-rep maximum based on your performance with submaximal weights. This provides you with safe strength targets before attempting potentially risky maximal lifts. Safety Note: Heavy weightlifting should always be performed with proper technique and appropriate spotting. This app provides estimates based on scientific formulas, but individual performance may vary based on experience level and training history. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

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.

Screenshots

One Rep Max4 screens
531 Strength4 screens

Verdict

The call

The clearest difference is review sentiment: 531 Strength at 94% against One Rep Max's 57%. 531 Strength also leads on rating (4.9 vs 4.4) and ratings volume (12K vs 185). One Rep Max's advantage is update cadence (every 6 days vs every 2 months) and iOS requirement (15.0 vs 18.0). On price, ads, 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. One Rep Max sells 2 in-app purchases, starting at $2.99 per month and 531 Strength sells 4 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

531 Strength holds the better App Store score, 4.9 against 4.4. That said, the two scores are not equally well evidenced: 531 Strength has 12K ratings behind it against 185, so its average is the more settled of the two. Written reviews point the same way: 57% of One Rep Max's written reviews are positive against 94% of 531 Strength's.

UpkeepUpdate frequency

One Rep Max ships an update every 6 days, 531 Strength every 2 months. The most recent releases landed on November 3, 2026 and November 5, 2026 respectively.

Scorecard5 real differences · 5 level
One Rep Max versus 531 Strength: the parameters behind the verdict, then further details
ParameterOne Rep Max531 Strength
PriceFreeFree
Rating4.4 (185 ratings)4.9 (12K ratings) — better
Positive reviews57.1% of reviews94.0% of reviews — better
Number of ratings18512K — better
Update frequencyEvery 6 days — betterEvery 2 months
AdsYesYes
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.0 — better18.0
Further details — not scored
Size52 MB26 MB
Age rating4+4+
DeveloperCharles VanderhoffHenrik Jachobsen

Customer experience

One Rep Max

All ratings185 ratings
Positive85.9%
Neutral2.7%
Negative11.4%
Written reviews56 reviews
Positive57.1%
Neutral10.7%
Negative32.1%

531 Strength

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

User reviews

One Rep Max

From 185 App Store ratings

What we love

  • 👍 Easy to use interface
  • 📊 Tracks progress with charts
  • ➕ Plate calculator bonus feature
  • 📈 Supports multiple 1RM formulas
  • 💪 Helpful for tracking RMs

Room to improve

  • 💰 Subscription required for features
  • 💸 Features moved behind paywall
  • 😩 Useless without subscription
  • 🚫 Basic features now paid
  • 💸 High subscription cost

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

Bugs and requests

One Rep Max

Reported bugs

13 issues
  • Features behind paywall
  • Forced ads
  • Deleted lifting history
  • Lost all logs with update
  • Weight limit restriction
Show 8 more
  • Reloads excessively
  • Wonky and now dead
  • Complicated and too much offered
  • Not intuitive for tracking
  • Buggy about dates and lifts
  • Cannot select other lifts
  • Only logs back squats
  • App copying content from clipboard

Requested features

7 requests
  • Allow editing of logs (date/time)
  • Manual entry for weight preferred over slider
  • Include different 1RM formulas (Epley, Brzycki)
  • Ability to create custom graphs
  • Fix weight limit restriction
Show 2 more
  • Allow logging of more than 1073 pounds
  • Update app

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

In-app purchases

2 purchases

One Rep Max

Subscriptions2
  • 1RM Pro Monthly$2.991 Month
  • 1RM Pro Annual7 Days trial$19.991 Year
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

Questions

Is One Rep Max free?
One Rep Max is free to download, with in-app purchases available.
Is 531 Strength free?
531 Strength is free to download, with in-app purchases available.
Which has better reviews, One Rep Max or 531 Strength?
531 Strength is rated higher. One Rep Max averages 4.4 out of 5 from 185 ratings, while 531 Strength averages 4.9 from 12K ratings.
Do One Rep Max or 531 Strength have ads?
Both One Rep Max and 531 Strength show ads.
Which is updated more often, One Rep Max or 531 Strength?
One Rep Max ships an update every 6 days, and 531 Strength every 2 months. Most recently, One Rep Max was updated on November 3, 2026 and 531 Strength on November 5, 2026.

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