Workshop & Large Sizes in Inches
Saw blades, grinder discs, paper and timber — metric sizes converted to inches.
Converting Larger Sizes
Above about 100 mm, most people care about the nearest whole or half inch rather than tiny fractions — but tools and materials are often sold in “nominal” sizes that are rounded. A disc sold as 230 mm is really a 9-inch disc with a metric label, and a 7-1/4″ saw blade is sold in Europe as 184 mm. Knowing the exact conversion stops you buying the wrong part.
Saw Blades and Grinder Discs
| Metric size | Decimal inches | Sold in inches as | Tool |
|---|---|---|---|
| 115 mm | 4.5276″ | 4-1/2″ (114.3 mm) | Angle grinder disc |
| 125 mm | 4.9213″ | 5″ (127.0 mm) | Angle grinder disc |
| 165 mm | 6.4961″ | 6-1/2″ (165.1 mm) | Circular saw blade |
| 184 mm | 7.2441″ | 7-1/4″ (184.15 mm) | Circular saw blade |
| 190 mm | 7.4803″ | 7-1/2″ (190.5 mm) | Circular saw blade |
| 230 mm | 9.0551″ | 9″ (228.6 mm) | Large angle grinder disc |
| 254 mm | 10.0000″ | 10″ (254.0 mm) | Table / mitre saw blade |
Paper Sizes in Inches
ISO paper sizes are defined in millimeters, so their inch sizes are never round numbers. US Letter is 8.5 × 11 in (215.9 × 279.4 mm) — slightly wider and shorter than A4.
| Size | Millimeters | Inches |
|---|---|---|
| A5 | 148 × 210 mm | 5.83 × 8.27 in |
| A4 | 210 × 297 mm | 8.27 × 11.69 in |
| A3 | 297 × 420 mm | 11.69 × 16.54 in |
Timber and Board Sizes
Metric timber is sold by its sawn size, so a 100 × 50 mm length is about 3.94 × 1.97 in — close to, but not the same as, a US “4 × 2” (which is actually 3.5 × 1.5 in after planing). Always compare the actual measurement, not the name.
Large Sizes: 100 to 300 mm
100 mm · 110 mm · 120 mm · 130 mm · 140 mm · 150 mm · 160 mm · 170 mm · 180 mm · 190 mm · 200 mm · 210 mm · 220 mm · 230 mm · 240 mm · 250 mm · 260 mm · 270 mm · 280 mm · 290 mm · 300 mm
Need a size in between? Every whole millimeter up to 300 mm has its own page — use the converter or the printable chart.