If you want to know 20mm is how many inches, the answer is 0.7874 inches. Rounded to two decimal places, it is 0.79 inches.
You can also write 20mm as about 25/32 inch. This is the closest common fraction on an inch ruler, but it is not an exact match.
In this guide, you will learn how to convert 20mm to inches, fractions, centimeters, and feet. You will also find a conversion chart and answers about diameter, width, rainfall, and pipe size.
How Many Inches Is 20mm?
20 millimeters equals about 0.7874 inches.
Here are the main conversions:
- 20mm = 0.7874 inches
- 20mm = 0.79 inches when rounded to two decimal places
- 20mm = 2 centimeters
- 20mm = 0.06562 feet
- 20mm is closest to 25/32 inch
There are exactly 25.4 millimeters in one inch. You can use this value to convert any millimeter measurement into inches.
20mm to Inches as a Fraction
If you need 20mm to inches as a fraction, the closest common ruler fraction is 25/32 inch.
This is an approximation. It is not an exact conversion.
| Inch Fraction | Millimeters |
| 1/4 inch | 6.35mm |
| 1/2 inch | 12.7mm |
| 5/8 inch | 15.875mm |
| 3/4 inch | 19.05mm |
| 25/32 inch | 19.84375mm |
| 13/16 inch | 20.6375mm |
| 7/8 inch | 22.225mm |
| 1 inch | 25.4mm |
20mm falls between 3/4 inch and 13/16 inch. It is closest to 25/32 inch.
Is 20mm Equal to 1/2 Inch?
No, 20mm is not equal to 1/2 inch.
- 20mm = 0.7874 inches
- 1/2 inch = 12.7mm
This means 20mm is much larger than 1/2 inch. It is closer to 3/4 inch, but it is still slightly larger.
How to Convert 20mm to Inches
You can use a simple formula to change millimeters into inches.
Formula:
Inches = Millimeters ÷ 25.4
For 20mm:
20 ÷ 25.4 = 0.7874015748
So, 20mm is about 0.7874 inches.
You can use the same formula for 25mm, 40mm, or any other measurement.
20mm to Inches Conversion Chart
This chart shows 20mm and other common millimeter values in inches.
| Millimeters | Inches |
| 5mm | 0.1969 |
| 6mm | 0.2362 |
| 8mm | 0.3150 |
| 10mm | 0.3937 |
| 12mm | 0.4724 |
| 15mm | 0.5906 |
| 18mm | 0.7087 |
| 19mm | 0.7480 |
| 20mm | 0.7874 |
| 21mm | 0.8268 |
| 22mm | 0.8661 |
| 25mm | 0.9843 |
| 30mm | 1.1811 |
| 40mm | 1.5748 |
| 50mm | 1.9685 |
Use this 20mm to inches chart to compare metric measurements with decimal inches.
25mm to Inches
25mm equals about 0.9843 inches.
Rounded to two decimal places, it is 0.98 inches. This is very close to one inch.
Here is a quick comparison:
- 20mm = 0.7874 inches
- 25mm = 0.9843 inches
- 25.4mm = 1 inch
20mm to Centimeters
To convert 20mm to cm, divide the value by 10.
20 ÷ 10 = 2
So, 20mm equals 2cm.
This is because 10 millimeters make one centimeter.
20mm to Feet
One foot contains 304.8 millimeters.
To convert 20mm to feet, divide 20 by 304.8.
20 ÷ 304.8 = 0.06562
So, 20mm is about 0.06562 feet.
This is a small part of one foot.
20mm x 20mm in Inches
If an item measures 20mm by 20mm, both sides have the same length.
Each side equals about 0.7874 inches.
So:
- 20mm = 0.7874 inches
- 20mm x 20mm = 0.7874 x 0.7874 inches
- Area = about 0.620 inches²
This conversion can help when measuring square items, tiles, or small parts.
How Many Inches Is 20mm on a Ruler?
20mm is about 0.7874 inches on an inch ruler.
It falls between:
- 3/4 inch (0.75 inches)
- 13/16 inch (0.8125 inches)
It is closest to 25/32 inch.
On a metric ruler, 20mm is the same as the 2cm mark.
How Many Inches Is a 20mm Diameter?
A 20mm diameter equals about 0.7874 inches.
Diameter means the distance across a round object through its center.
For example, a round bead or metal part with a 20mm diameter is about 0.79 inches wide across its center.
How Many Inches Is 20mm of Rain?
20mm of rain equals about 0.7874 inches of rainfall.
This means rain would form a water layer about 0.79 inches deep on a flat surface if none of the water drained away or soaked into the ground.
How Many Inches Is 20mm in Width?
A width of 20mm equals about 0.7874 inches.
The same conversion works for length, height, thickness, and width. The unit does not change based on what you are measuring.
How Many Inches Is 15–20mm?
A range of 15–20mm equals about 0.5906–0.7874 inches.
| Millimeters | Inches |
| 15mm | 0.5906 |
| 16mm | 0.6299 |
| 17mm | 0.6693 |
| 18mm | 0.7087 |
| 19mm | 0.7480 |
| 20mm | 0.7874 |
This chart helps when a product or guide gives a measurement between 15mm and 20mm.
How Many Inches Is 40mm x 20mm?
A size of 40mm x 20mm equals about 1.5748 x 0.7874 inches.
Here is the breakdown:
- 40mm = 1.5748 inches
- 20mm = 0.7874 inches
Rounded to two decimal places, the size is about 1.57 x 0.79 inches.
20mm Pipe Size in Inches
A 20mm pipe measurement may refer to its outside diameter, inside diameter, or nominal size.
If the actual pipe diameter is 20mm, it equals about 0.7874 inches.
However, pipe size names do not always match the actual outside measurement. Different pipe standards may use nominal sizes.
Before buying a pipe, check its standard, outside diameter, and inside diameter. Do not assume that every pipe marked 20mm has the same inch size.
How to Use a Millimeter to Inch Calculator
An online conversion calculator can change millimeters into inches in a few steps.
- Open a millimeter to inch calculator.
- Enter 20 in the millimeter box.
- Select inches as the output unit.
- Read the result.
The answer should be about 0.7874 inches.
You can also enter 25, 40, or another value to convert it into inches.
Frequently Asked Questions
20mm equals about 0.7874 inches. Rounded to two decimal places, it is 0.79 inches.
20mm is closest to 25/32 inch on a common fractional ruler. This is an approximation, not an exact match.
20mm equals 2 centimeters.
20mm equals about 0.06562 feet.
No. 1/2 inch equals 12.7mm. A 20mm measurement is about 0.7874 inches.
A 20mm diameter is about 0.7874 inches across.
20mm of rain equals about 0.7874 inches of rainfall.
25mm equals about 0.9843 inches, which is close to one inch.
An actual 20mm pipe diameter equals about 0.7874 inches. However, nominal pipe sizes depend on the pipe standard and may not match the real diameter.
20mm x 20mm equals about 0.7874 x 0.7874 inches.
Final Answer
20mm is equal to 0.7874 inches, or about 0.79 inches. Its closest common ruler fraction is 25/32 inch.
It also equals 2cm and about 0.06562 feet. You can convert any millimeter value to inches by dividing it by 25.4.
Hi, I’m Marcus. I write conversion guides that turn confusing numbers into clear answers. Each article gives the exact value, a simple rounded version and real-life examples, so you can measure with confidence whether you’re shopping, building or just curious.