Comparison

Ruler vs Scale

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

Head to head
About

Ruler

This app displays various measurement scales for length, including meters and inches. It allows users to set magnification ratios and reduced scales for different applications. Users can calibrate the ruler and adjust PPI settings for accurate measurements.

Highlights
  • Display various measurement scales
  • Set magnification ratios
  • Set reduced scales
  • Measure in meters and inches
  • Free mode for custom scales
  • Calibration for accuracy
  • PPI setting
Features
Read full description

Scale Ruler is the simple application to display the scale of various measurement units. ※ Warning: - The accuracy of the scales cannot be guaranteed. - Calibration and PPI values ​​will be reset when the model changes. - Set the PPI value only when the model is undecided. - When you change the PPI value, perform calibration after the change. ■How to use: ■Select mode In UNLOCKED state, after choosing measurement unit, magnification ratio and reduced scale, the scale is displayed. ■Free mode When dragging the screen at UNLOCK, you can set the scale in the range 1: 1 to 1: 100. When you press and hold the scale value, the keyboard is displayed and you can enter the scale. You can lock the scale on the ruler with a switch. Sorry for the advertisement during unlocking. After In-App Purchase, your ads will no longer be displayed. Specification of Scale Ruler - measure length meter,inches - magnification ratio 50% , 70.7% , 100% , 141% , 200% - reduced scale  for meter    1:100 , 1:150 , 1:200 , 1:250 , 1:300 , 1:400 , 1:500 , 1:600  for inch   1:1 , 1:1.5 , 1:2 , 1:2.5 , 1:3 , 1:4 , 1:5 , 1:6  for inch(Architectural)   1:1 , 1:2 , 1:4 , 1:8 , 1:12 , 1:16 , 1:24 , 1:32 , 1:48 , 1:64   1:96 , 1:128 , 1:192 , 1:384  for inch(Engineering) 1:120 , 1:240 , 1:360 , 1:480 , 1:600 , 1:720 1:800 , 1:960 , 1:1080 ■ Settings - Calibration - PPI (pixels per inch) setting - In-app purchase (ads not displayed) - In-app purchase restoration ■ Calibration Adjust the length of the ruler. Use the correct ruler for adjustment. "Calibration" button: Records the adjusted state and reflects the calibration result on the ruler. "Reset" button: Returns the adjustment status to the specified value. It will not be recorded. "Initialize" button: Returns the adjustment status to the specified value and reflects it on the ruler. * Caution: The calibration value will be reset when the model changes. ■ PPI (pixels per inch) setting If the model is undecided, check the PPI value of the model before setting the PPI value. * Please set only when the model is undecided. "OK" button: Record the entered PPI value and reflect it on the ruler display. "Initialize" button: Returns the PPI value to the specified value and reflects it on the ruler. * Caution: The PPI value will be reset when the model changes.

About

Scale

This tool simplifies scaling and unit conversions for creators. It offers a vast library of scales and units, allowing for seamless adjustments and precise calculations. Customize the interface to match your workflow and focus on your projects.

Highlights
  • Extensive database of scales and units
  • Customizable scales and units
  • Imperial and metric conversions
  • Fractional and decimal rounding
  • Conversion history
  • Customizable buttons
Features
Read full description

Build models and other scaled objects faster and more accurately with Scale-o-Tron. Model builders, architects, tabletop gamers, doll makers, train enthusiasts, sculptors, set designers, and anyone else who builds to scale can focus on their craft instead of on conversions. Features: • Convert from any scale and unit to any other scale and unit. You are not limited to converting from 1:1. • Mix scales and units in a calculation; Scale-o-Tron handles the conversions. • A large library of common scales, organized for quick access, plus your own custom scales. • Metric and imperial units, including historical units for old schematics and literature. • Fine control over numerical precision and display. Fraction rounding keeps imperial measurements practical. • Customize and save as many calculator layouts as you like, each suited to a type of project. • Adjust button and display size to your preference. Whether you build from scratch or from kits, Scale-o-Tron keeps your project accurate and lets you focus on the build. Visit the website to learn how Scale-o-Tron can help with your projects.

Screenshots

Ruler4 screens
Scale4 screens

Verdict

The call

The clearest difference is price: Ruler at Free against Scale's $4.99. Ruler also leads on device support (3 vs 1) and iOS requirement (15.0 vs 17.0). Scale's advantage is rating (4.2 vs 3.7) and in-app purchases (none vs 1). On review sentiment and ratings volume 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

Ruler is free to download; Scale costs $4.99 up front. Ruler sells 1 one-off in-app purchase. Scale asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Scale holds the better App Store score, 4.2 against 3.7. Both are backed by a comparable volume of ratings — 3 and 5 respectively. Written reviews point the same way: 63% of Ruler's written reviews are positive against 67% of Scale's.

UpkeepUpdate frequency

Ruler ships an update every 5 months, Scale every 8 days. The most recent releases landed on November 1, 2026 and November 2, 2026 respectively.

Scorecard8 real differences · 2 level
Ruler versus Scale: the parameters behind the verdict, then further details
ParameterRulerScale
PriceFree — better$4.99
Rating3.7 (3 ratings)4.2 (5 ratings) — better
Positive reviews63.0% of reviews66.7% of reviews — better
Number of ratings35 — better
Update frequencyEvery 5 monthsEvery 8 days — better
AdsYesNo — better
In-app purchasesYesNo — better
MonetizationFree with in-app purchases — betterPaid
DevicesiPhone, iPad, iPod — betteriPhone
Requires iOS15.0 — better17.0
Further details — not scored
Size4 MB3 MB
Age rating4+4+
Developermitsunori oishiMizmovac, Inc

Customer experience

Ruler

All ratings3 ratings
Positive66.7%
Neutral0.0%
Negative33.3%
Written reviews27 reviews
Positive63.0%
Neutral3.7%
Negative33.3%

Scale

All ratings5 ratings
Positive80.0%
Neutral0.0%
Negative20.0%
Written reviews3 reviews
Positive66.7%
Neutral0.0%
Negative33.3%

In-app purchases

1 purchases

Ruler

One-time1
  • Hide Ads$0.99
None

Scale

No in-app purchases

Questions

Is Ruler free?
Ruler is free to download, with in-app purchases available.
Is Scale free?
Scale costs $4.99, with no in-app purchases.
Which has better reviews, Ruler or Scale?
Scale is rated higher. Ruler averages 3.7 out of 5 from 3 ratings, while Scale averages 4.2 from 5 ratings.
Do Ruler or Scale have ads?
Ruler shows ads; Scale does not.
Which is updated more often, Ruler or Scale?
Ruler ships an update every 5 months, and Scale every 8 days. Most recently, Ruler was updated on November 1, 2026 and Scale on November 2, 2026.

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