Scales HD vs Architects Ruler
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- Architectural US Scales
- Engineering US Scales
- Metric SI Scales
- Tape Measure Tool
- Spirit Level Tool
- Flip Scales Option
- Music Control
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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.
Architects Ruler
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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
Verdict
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
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.
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.
| Parameter | Scales HD | Architects Ruler |
|---|---|---|
| Price | $3.99 | Free — better |
| Rating | 4.2 (5 ratings) — better | — |
| Positive reviews | 50.0% of reviews | — |
| Number of ratings | 5 — better | — |
| Update frequency | Every 95 months | Every 3 months — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Paid | — |
| Devices | iPhone, iPad, iPod — better | iPhone |
| Requires iOS | 15.0 — better | 26.0 |
| Further details — not scored | ||
| Size | 7 MB | 4 MB |
| Age rating | 4+ | 4+ |
| Developer | Marcelo Mejia Cobo | Gijs Raggers |
In-app purchases
Scales HD
No in-app purchases
Architects Ruler
- Lifetime scales menu$0.99
Questions
Is Scales HD free?
Is Architects Ruler free?
Do Scales HD or Architects Ruler have ads?
Which is updated more often, Scales HD or Architects Ruler?
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