Calculate DPI from dots and a length in cm, or solve for the pixels or print size you need at a target DPI, with a viewing-distance quality check.
Cm To Dpi Formula
The following formula is used to calculate DPI (or PPI) when you know the number of dots/pixels along a measured length and the physical length in centimeters.
Variables:
- DPI is the dots (pixels) per inch
- D is the number of dots/pixels along the measured length (for example, the image width in pixels)
- C is the physical length in centimeters that corresponds to D
To calculate the DPI, divide the number of dots/pixels along the measured length by the length in inches. Since 1 inch equals 2.54 cm, you can convert centimeters to inches by dividing by 2.54, giving the formula above.
| Centimeters (cm) | Pixels @ 72 dpi | Pixels @ 96 dpi | Pixels @ 150 dpi | Pixels @ 300 dpi |
|---|---|---|---|---|
| 0.5 | 14.173 | 18.898 | 29.528 | 59.055 |
| 1 | 28.346 | 37.795 | 59.055 | 118.110 |
| 2 | 56.693 | 75.591 | 118.110 | 236.220 |
| 2.54 (1 in) | 72.000 | 96.000 | 150.000 | 300.000 |
| 3 | 85.039 | 113.386 | 177.165 | 354.331 |
| 5 | 141.732 | 188.976 | 295.276 | 590.551 |
| 7.5 | 212.598 | 283.465 | 442.913 | 885.827 |
| 10 | 283.465 | 377.953 | 590.551 | 1181.102 |
| 12.7 (5 in) | 360.000 | 480.000 | 750.000 | 1500.000 |
| 15 | 425.197 | 566.929 | 885.827 | 1771.654 |
| 20 | 566.929 | 755.906 | 1181.102 | 2362.205 |
| 21 (A4 width) | 595.276 | 793.701 | 1240.157 | 2480.315 |
| 21.59 (8.5 in) | 612.000 | 816.000 | 1275.000 | 2550.000 |
| 25.4 (10 in) | 720.000 | 960.000 | 1500.000 | 3000.000 |
| 27.94 (11 in) | 792.000 | 1056.000 | 1650.000 | 3300.000 |
| 29.7 (A4 height) | 841.890 | 1122.520 | 1753.937 | 3507.874 |
| 30 | 850.394 | 1133.858 | 1771.654 | 3543.307 |
| 40 | 1133.858 | 1511.811 | 2362.205 | 4724.409 |
| 50 | 1417.323 | 1889.764 | 2952.756 | 5905.512 |
| 60 | 1700.787 | 2267.717 | 3543.307 | 7086.614 |
| Pixels (≈ dots) along one dimension are calculated as: px = cm × DPI ÷ 2.54. Assumes 1 inch = 2.54 cm. | ||||
What is Cm To Dpi (PPI)?
Cm to DPI (more precisely PPI for digital images) refers to finding pixel density when you know a physical length in centimeters and the number of dots/pixels along that same length. This is often used in printing and graphic design to relate an image’s pixel dimensions to a desired print size. DPI is a printing term (printer dots per inch), while PPI is the usual term for images/screens (pixels per inch), but people often use “DPI” informally for both.
How to Calculate Cm To Dpi?
The following steps outline how to calculate the Cm To Dpi using the formula: DPI = D / (C / 2.54).
- First, determine the number of dots/pixels along the measured length (D) (for example, the image width in pixels).
- Next, determine the corresponding physical length in centimeters (C).
- Next, substitute the values of D and C into the formula: DPI = D / (C / 2.54).
- Finally, calculate the DPI (PPI).
- After inserting the variables and calculating the result, check your answer with the calculator above.
Example Problem :
Use the following variables as an example problem to test your knowledge.
Dots/pixels along the measured length (D) = 500
Length in centimeters (C) = 10
DPI = 500 / (10 / 2.54) ≈ 127.00
