Comparison

Scales HD vs Architects Ruler

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

Head to head
About

Scales HD

This app provides a digital architectural and engineering scale ruler with various US and Metric scales. It includes tools like a tape measure and spirit level, with options to flip scales and lock scrolling. Control your music library directly from the app.

Highlights
  • Architectural US Scales
  • Engineering US Scales
  • Metric SI Scales
  • Tape Measure Tool
  • Spirit Level Tool
  • Flip Scales Option
  • Music Control
Features
Read full description

Scales HD puts a real architect's and engineer's scale rule in your pocket, drawn at true physical size on every iPhone and iPad, so a millimetre on screen is a millimetre on your drawing. Around it: a CAD, Room Scan, a PDF blueprint reader, a construction calculator, notes and more. TRUE SIZE ON EVERY DEVICE • Exact screen density for every iPhone, iPad and iPhone Duo model • Zero at the screen edge or the device edge; optional calibration TRIANGULAR SCALES, JUST LIKE THE REAL ONE • Turn the scale to its other sides; all four edges on each, the original artwork's grooves and faces • One tap prints the US ↔ metric equivalent beside every scale: 1:48 next to 1/4" = 1'-0" • Two measuring lines read in both edge scales at once, with snapping EVERY SCALE YOU USE • US architectural 1/32" to 12" = 1'-0"; engineering 1" = 10' to 120' • Metric 1:1 to 1:10000, civil and survey; mechanical; UK and Japanese rules • Enlargements, maps 1:24000 to 1:250000, model rail and kits; read any edge at ×10 or ×100 • Your own scales, any ratio, in your own color CAD • Walls, doors, windows, furniture and dimensions at real size; freehand too • Booleans, trim, extend, fillet, offset, arrays, layers, edit in place • About 700 templates: full project sets, homes, interiors, ADA, landscape, sections, details, MEP • Export true-scale PDF or SVG, PNG, DXF and DWG; open DWG and DXF drawings ROOM SCAN (LiDAR iPhone and iPad) • Scan rooms into floor plans, elevations, a room schedule and 3D models • Stitch rooms, set a measured length, export USDZ, OBJ, glTF, IFC and DXF, or open as a CAD drawing BLUEPRINTS • PDF drawing sets as sheets you can search and bookmark • Set the sheet's scale and measure lengths, areas and counts; mark up with clouds, callouts and stamps • Compare revisions; stand a plan in the room at 1:1 in AR CONSTRUCTION CALCULATOR • Feet-inch-fraction and metric, mixed freely: 5'-3 1/2" + 80 cm • Areas, volumes, diagonal, pitch, stairs, circles; a tape of your calculations NOTES THAT SKETCH • Lists, checklists and a full row of symbols, fractions and units over the keyboard • Drop in pictures, PDF pages and CAD drawings, then move and size them; text flows around • Quick sketch stickies: draw with a finger or Apple Pencil in any color and pen VOICE • A microphone on every screen: "use 1 to 50", "3 feet 4 inches plus 2 feet", "place a queen bed against the north wall". Understood on the device MORE TOOLS • Unit converter: 11 families, 94 units • Scale converter: drawing ↔ real size, redraw at another scale, find a drawing's scale • Protractor: read an angle on paper at true size, between two surfaces by tilt, or on the iPhone Duo's hinge, with the supplement, the miter and the saw setting • Spirit level with the original bubble, compass, tape, cutting board, haptics MADE FOR iPHONE DUO • Closed, every tool fits the outer screen around the camera; open, the big screen; half open, the calculator, level, compass, protractor and blueprints keep off the fold; the hinge itself is a protractor iPhone and iPad, iCloud sync between your devices. No ads, no tracking, no account, no subscription.

About

Architects Ruler

Features
Read full description

Architects Ruler is made by architects for architects. And designers. Simple and convenient, a quick tool to get grip on all dimensions on any scale.

Screenshots

Scales HD4 screens
Architects Ruler3 screens

Verdict

The call

The clearest difference is price: Architects Ruler at Free against Scales HD's $3.99. Architects Ruler also leads on update cadence (every 3 months vs every 95 months). Scales HD's advantage is in-app purchases (none vs 1) and device support (3 vs 1). On ads 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

Architects Ruler is free to download; Scales HD costs $3.99 up front. Architects Ruler sells 1 one-off in-app purchase. Scales HD asks for nothing beyond the download.

UpkeepUpdate frequency

Scales HD ships an update every 95 months, Architects Ruler every 3 months. The most recent releases landed on November 1, 2026 and October 30, 2026 respectively.

Scorecard5 real differences · 5 level
Scales HD versus Architects Ruler: the parameters behind the verdict, then further details
ParameterScales HDArchitects Ruler
Price$3.99Free — better
Rating4.2 (5 ratings) — better—
Positive reviews50.0% of reviews—
Number of ratings5 — better—
Update frequencyEvery 95 monthsEvery 3 months — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaid—
DevicesiPhone, iPad, iPod — betteriPhone
Requires iOS15.0 — better26.0
Further details — not scored
Size7 MB4 MB
Age rating4+4+
DeveloperMarcelo Mejia CoboGijs Raggers

In-app purchases

None

Scales HD

No in-app purchases

1 purchases

Architects Ruler

One-time1
  • Lifetime scales menu$0.99

Questions

Is Scales HD free?
Scales HD costs $3.99, with no in-app purchases.
Is Architects Ruler free?
Architects Ruler is free to download, with in-app purchases available.
Do Scales HD or Architects Ruler have ads?
Neither Scales HD nor Architects Ruler shows ads.
Which is updated more often, Scales HD or Architects Ruler?
Scales HD ships an update every 95 months, and Architects Ruler every 3 months. Most recently, Scales HD was updated on November 1, 2026 and Architects Ruler on October 30, 2026.

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