20 mm to inches
Instant conversion for 20 mm — decimal inches, the nearest 1/64 fraction , and how far off common imperial sizes are, using the same engine as the mm to inches hub.
20 mm to inches conversion
- Decimal inches
- 0.7874
- Nearest 1/64
- 25/32 in (−0.156 mm)
- Feet + inches
- 0 ft 0.787 in
The inches fraction result is rounded to the nearest 1/64 fraction.
20 millimeters is equal to 0.7874 inches.
- Decimal inches: 0.7874 in
- Nearest 1/64: 25/32 in (-0.156 mm from the exact size)
How many inches is 20 mm?
20 millimeters is equal to 0.7874 inches. That is the exact international conversion ( 1 in = 25.4 mm). On a fractional chart, the nearest 1/64 is 25/32 in.
How to convert 20 mm to inches
Formula: inches = millimeters ÷ 25.4 (exact). Or multiply by 0.0393701 for a quick estimate of the same definition.
- Start with 20 mm.
- Divide by 25.4: 20 ÷ 25.4 = 0.7874 in.
- Reverse check: 0.7874 × 25.4 = 20 — the conversion round-trips cleanly.
About the fraction result
The decimal column is exact (shown to four places). The fraction is the nearest 1/64 approximation used on rulers and bit charts — so the two can disagree. Here, 20 mm = 0.7874 in exactly, while 25/32 in differs by -0.156 mm. The converter disclaimer (“rounded to the nearest 1/64 fraction”) exists so that difference is never mistaken for a data error.
Is 20 mm the same as 3/4 inch?
No. 3/4 in equals 19.05 mm — 0.95 mm smaller than 20 mm. Pipe, tubing, and photo frames labeled 20 mm are not a 3/4-inch size. The nearest 1/64 is 25/32 in (19.84 mm), about 0.16 mm undersize.
Compared with 3/4 in (19.05 mm): 20 mm is +0.950 mm (metric size is larger).
This page is for specification checks — drill bits, sockets, tubing, and stock — not body measurements. For shop picks across many metric diameters, see the drill bit & socket mm to inches chart.
20 mm to inches conversion chart
Local density around 20 mm (±1 mm, every 0.1 mm). For the full 0–100 mm table, use the mm to inches hub chart.
| mm | inches (decimal) | inches (nearest 1/64) |
|---|---|---|
| 19 | 0.7480 | 3/4 |
| 19.1 | 0.7520 | 3/4 |
| 19.2 | 0.7559 | 3/4 |
| 19.3 | 0.7598 | 49/64 |
| 19.4 | 0.7638 | 49/64 |
| 19.5 | 0.7677 | 49/64 |
| 19.6 | 0.7717 | 49/64 |
| 19.7 | 0.7756 | 25/32 |
| 19.8 | 0.7795 | 25/32 |
| 19.9 | 0.7835 | 25/32 |
| 20 | 0.7874 | 25/32 |
| 20.1 | 0.7913 | 51/64 |
| 20.2 | 0.7953 | 51/64 |
| 20.3 | 0.7992 | 51/64 |
| 20.4 | 0.8031 | 51/64 |
| 20.5 | 0.8071 | 13/16 |
| 20.6 | 0.8110 | 13/16 |
| 20.7 | 0.8150 | 13/16 |
| 20.8 | 0.8189 | 13/16 |
| 20.9 | 0.8228 | 53/64 |
| 21 | 0.8268 | 53/64 |
FAQ
How many inches is 20 mm?
20 millimeters is equal to 0.7874 inches. The nearest 1/64 fraction is 25/32 in.
Is 20 mm the same as 3/4 inch?
No. 3/4 in = 19.05 mm, so 20 mm is 0.95 mm larger. Prefer a true 20 mm size when the drawing is metric.
What is 20 mm in fractional inches?
The exact decimal is 0.7874 in. Rounded to the nearest 1/64, that is 25/32 in — about 0.156 mm smaller than exact 20 mm.