20 cm is approximately 189.0 dpi.
This result comes from converting centimeters to dots per inch (dpi) by using the relationship between centimeters and inches, where 1 inch equals 2.54 cm. Dpi measures the number of dots within one inch, so converting length in cm to dpi involves converting cm to inches, then scaling by dpi.
Conversion Tool
Result in dpi:
Conversion Formula
The formula to convert centimeters (cm) to dots per inch (dpi) relies on converting length units first, because dpi measures dots per inch, not per cm. Since 1 inch equals 2.54 cm, to find dpi from cm, the value in cm is divided by 2.54 which gives the length in inches. Then multiplying by a standard dpi value (commonly 96 dpi for screens) gives the dpi.
Formula:
dpi = (cm / 2.54) × 96
Why it works:
– Centimeters are a metric length unit, inches imperial.
– dpi counts dots in one inch, so cm must convert to inches.
– Multiplying inches by dpi gives total dots for that length.
Example:
For 20 cm:
Step 1: Convert cm to inches: 20 ÷ 2.54 = 7.874 inches
Step 2: Multiply inches by 96 dpi: 7.874 × 96 = 189.98 dpi (rounded to 189.0 dpi)
Conversion Example
- 15 cm to dpi:
- Convert 15 cm to inches: 15 ÷ 2.54 = 5.905 inches
- Multiply by 96 dpi: 5.905 × 96 = 566.88 dpi
- Final result: 566.88 dpi
- 30 cm to dpi:
- Convert to inches: 30 ÷ 2.54 = 11.811 inches
- Multiply by 96 dpi: 11.811 × 96 = 1133.86 dpi
- Result is 1133.86 dpi
- 5 cm to dpi:
- 5 ÷ 2.54 = 1.9685 inches
- 1.9685 × 96 = 189.1 dpi
- So 5 cm equals about 189.1 dpi
- 10 cm to dpi:
- 10 ÷ 2.54 = 3.937 inches
- 3.937 × 96 = 378.0 dpi
- 10 cm converts to 378.0 dpi
Conversion Chart
| cm | dpi |
|---|---|
| -5.0 | -189.0 |
| 0.0 | 0.0 |
| 5.0 | 189.0 |
| 10.0 | 378.0 |
| 15.0 | 567.0 |
| 20.0 | 756.0 |
| 25.0 | 945.0 |
| 30.0 | 1134.0 |
| 35.0 | 1323.0 |
| 40.0 | 1512.0 |
| 45.0 | 1701.0 |
This chart shows how many dots per inch correspond to length values in cm. To use it, find the cm value on the left, then see the corresponding dpi on the right. Negative values indicate dpi in opposite direction or measurement errors. Useful for quick reference without calculation.
Related Conversion Questions
- How many dpi are in 20 centimeters?
- What is the dpi equivalent of 20 cm for printing?
- Can I convert 20 cm directly to dpi for screen resolution?
- How do you calculate dpi from 20 cm measurement?
- Is 20 cm equal to 189 dpi or more?
- What dpi size corresponds to a 20 cm image?
- How does 20 cm convert to dpi on a 96 dpi display?
Conversion Definitions
cm: Centimeter is a unit of length in the metric system equal to one hundredth of a meter. It measures small distances or sizes and is widely used in science, engineering, and everyday measurements worldwide. 1 cm equals 10 millimeters or about 0.3937 inches.
dpi: Dots per inch (dpi) measures spatial printing or video dot density. It refers the number of individual dots that can be placed in a line within the span of 1 inch. Higher dpi means better image resolution, sharper images, and more detailed displays or prints.
Conversion FAQs
Can dpi be directly converted from cm without knowing resolution?
No, dpi depends on device or printing resolution, so assuming a standard dpi value is necessary. Converting cm to dpi requires assuming the dpi standard (like 96 dpi for screens). Without this, conversion lacks context and accuracy.
Why does the conversion multiply by 96 in the formula?
The number 96 represents a common screen resolution dpi, often used for computer displays. Multiplying by 96 converts inches to number of dots on that screen. Different devices may have higher or lower dpi, changing the conversion result.
What happens if dpi is calculated for negative cm values?
Negative cm values produce negative dpi, which don’t represent real physical measurements. This usually means input error or direction in measurement. Negative dpi doesn’t have practical meaning in printing or display contexts.
Is dpi the same as pixels per inch (ppi)?
Though often used interchangeably, dpi and ppi are different. PPI refers to pixels per inch on digital screens, while dpi counts dots per inch in printing. Printers use dpi to describe ink dot density, which can differ from screen pixel density.
How accurate is the cm to dpi conversion for printing?
Accuracy depends on printer resolution and settings. The formula gives a theoretical dpi based on length conversion but real print dpi may vary due to printer hardware, ink spread, and paper type. Always check device specs for precise dpi values.