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Drawing scale calculator

Measure something on a printed sheet, get the real dimension. Work the other way to check a drawing’s scale against a dimension it states. Metric and imperial. Nothing leaves this page.

1.0 On the sheet → on site

What is it really?

A sheet printed at anything other than full size is the usual reason a measurement disagrees with a stated dimension. Check one dimension the drawing prints before you trust the rest.

2.0 On site → on the sheet

How long will it draw?

3.0 An unmarked sheet

What scale is this drawing?

Find a dimension the drawing states, measure that same line on the sheet, and put both here.

The nearest standard scale is named only when the number lands within a few per cent of it. A ratio between two scales usually means the print was resized.

4.0 Units

Metric and imperial

5.0 Sheet sizes

What size is the sheet in front of you?

SheetMillimetresInches
ISO A0841 × 118933.1 × 46.8
ISO A1594 × 84123.4 × 33.1
ISO A2420 × 59416.5 × 23.4
ISO A3297 × 42011.7 × 16.5
ISO A4210 × 2978.3 × 11.7
ANSI B (Ledger)279 × 43211 × 17
ANSI D559 × 86422 × 34
ANSI E864 × 111834 × 44
ARCH D610 × 91424 × 36
ARCH E1762 × 106730 × 42

Measuring a whole set this way takes an afternoon.

Blueprint Auditor reads the scale off the title block, measures areas and lengths off the sheet, and writes the quantities out as a workbook whose totals are formulas. The trial takes a card, and runs on your own drawings.