Millimeters of Rain to inches of rain converter
Convert millimeters of rain to inches of rain instantly with a fast mm rain to in rain calculator.
About converting millimeters of rain to inches of rain
Why rainfall totals are often compared in two systems
Rainfall reports, forecast models, and local weather summaries do not always use the same measurement system. Millimeters are common in many countries and in technical weather products, while inches remain familiar in the United States for storm totals and local forecasts. That is why mm to inches rain is a frequent lookup during storms, travel planning, and climate comparisons.
Rainfall conversion formula
The conversion is straightforward: divide millimeters of rain by 25.4 to get inches of rain. A rainfall total of 25.4 mm equals exactly 1 inch, 50 mm is about 1.97 inches, and 100 mm is about 3.94 inches. Those reference points make it easier to understand whether a forecast suggests light rain, a soaking event, or a more serious storm total.
When this rainfall conversion is useful
This conversion is useful for weather briefings, hydrology notes, forecast comparisons, and translating storm totals into the scale that feels most familiar locally. Instead of estimating or switching tools mid-report, a dedicated mm to inches rain page keeps the conversion fast and easy to check.
Formula
live referenceUse the same conversion rule shown below in the widget, examples, and table on this page.
inch of rain = millimeter of rain x 0.03937
25.4 mm rain x 0.03937 = 1 in rain
Example conversions
30 presetsQuick reference values for the most common millimeters of rain to inches of rain lookups.
0.1 mm rain
0.0039 in rain
0.5 mm rain
0.0197 in rain
1 mm rain
0.0394 in rain
2 mm rain
0.0787 in rain
5 mm rain
0.1969 in rain
10 mm rain
0.3937 in rain
15 mm rain
0.5906 in rain
20 mm rain
0.7874 in rain
25 mm rain
0.9843 in rain
25.4 mm rain
1 in rain
30 mm rain
1.1811 in rain
40 mm rain
1.5748 in rain
50 mm rain
1.9685 in rain
60 mm rain
2.3622 in rain
75 mm rain
2.9528 in rain
100 mm rain
3.937 in rain
125 mm rain
4.9213 in rain
150 mm rain
5.9055 in rain
200 mm rain
7.874 in rain
250 mm rain
9.8425 in rain
300 mm rain
11.811 in rain
400 mm rain
15.748 in rain
500 mm rain
19.685 in rain
600 mm rain
23.622 in rain
750 mm rain
29.5276 in rain
1,000 mm rain
39.3701 in rain
1,250 mm rain
49.2126 in rain
1,500 mm rain
59.0551 in rain
2,000 mm rain
78.7402 in rain
3,000 mm rain
118.1102 in rain
Conversion table
30 rows| mm rain | in rain |
|---|---|
| 0.1 mm rain | 0.0039 in rain |
| 0.5 mm rain | 0.0197 in rain |
| 1 mm rain | 0.0394 in rain |
| 2 mm rain | 0.0787 in rain |
| 5 mm rain | 0.1969 in rain |
| 10 mm rain | 0.3937 in rain |
| 15 mm rain | 0.5906 in rain |
| 20 mm rain | 0.7874 in rain |
| 25 mm rain | 0.9843 in rain |
| 25.4 mm rain | 1 in rain |
| 30 mm rain | 1.1811 in rain |
| 40 mm rain | 1.5748 in rain |
| 50 mm rain | 1.9685 in rain |
| 60 mm rain | 2.3622 in rain |
| 75 mm rain | 2.9528 in rain |
| 100 mm rain | 3.937 in rain |
| 125 mm rain | 4.9213 in rain |
| 150 mm rain | 5.9055 in rain |
| 200 mm rain | 7.874 in rain |
| 250 mm rain | 9.8425 in rain |
| 300 mm rain | 11.811 in rain |
| 400 mm rain | 15.748 in rain |
| 500 mm rain | 19.685 in rain |
| 600 mm rain | 23.622 in rain |
| 750 mm rain | 29.5276 in rain |
| 1,000 mm rain | 39.3701 in rain |
| 1,250 mm rain | 49.2126 in rain |
| 1,500 mm rain | 59.0551 in rain |
| 2,000 mm rain | 78.7402 in rain |
| 3,000 mm rain | 118.1102 in rain |
About this converter
tool notesRainfall totals are easy to misread when forecast sources switch between metric and imperial reporting. One service may describe a storm in millimeters, while a local weather report uses inches of rain. This hub keeps rainfall conversion focused on that weather use case so you can compare totals, brief conditions, and read hydrology-style references without second-guessing what the number means.
How many inches of rain are in 1 mm?
1 millimeter of rain equals about 0.0393701 inches of rain.
What is the formula to convert mm to inches rain?
Divide millimeters of rain by 25.4 to convert them to inches of rain.
When is mm to inches rain conversion useful?
It is useful for forecast comparisons, storm reports, and translating rainfall totals between metric and US weather references.