Authoritative definitions of the International System of Units and SI prefixes.
Unit conversion
Dots per inch to Pixels per inch Converter
1 dpi = 1 ppi. Enter a value to convert dpi to ppi, then use the formula and table below. Displayed digits may be rounded.
Pixel densityInstant result
Decimals
Formula result = input × 1 ÷ 1. 1 dpi = 1 ppi
Nonzero results too small for the selected decimal places use scientific notation.
Nonzero results too small for the selected decimal places use scientific notation.
Common examples
One value, several units
Pixels per inch1 ppi
Pixels per centimetre0.3937 ppcm
Dots per centimetre0.3937 dpcm
Conversion table
| dpi | ppi |
|---|---|
| 1 dpi | 1 ppi |
| 2 dpi | 2 ppi |
| 5 dpi | 5 ppi |
| 10 dpi | 10 ppi |
| 25 dpi | 25 ppi |
| 50 dpi | 50 ppi |
| 100 dpi | 100 ppi |
Conversion chart
1 dpi1 ppi
5 dpi5 ppi
10 dpi10 ppi
25 dpi25 ppi
50 dpi50 ppi
Worked example
1 dpi = 1 ppi. Apply the selected conversion formula to other input values.
Unit definition
Dots per inch (dpi) One dots per inch equals 1 pixel per inch.
Unit history
Dots per inch is represented here using its modern SI definition or an internationally accepted relationship to an SI base unit.
Step by step
1. Parse the value, including fractions.
2. Convert dpi to pixel per inch.
3. Convert the base value to ppi and apply your display precision.
Understand the result before using it
Dots per inch to Pixels per inch converts a value measured in Dots per inch (dpi) into the equivalent value in Pixels per inch (ppi). The numerical value changes because the size and definition of the selected unit changes; the underlying quantity does not.
Calculated result
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.
Formula, assumptions, and example
Formula
result = input × 1 ÷ 1
Assumptions
- Dots per inch and Pixels per inch represent the same pixel density quantity.
- The input is expressed in dpi; the output is expressed in ppi.
- The unit definitions and conventional relationship shown on this page apply.
Worked example
1 dpi = 1 ppi. For another value, apply the same relationship and round only to the precision your source measurement supports.
When to use it
Good uses
- Read a dpi measurement in a document that expects ppi.
- Compare a dots per inch value with a value reported in pixels per inch.
- Check the dpi to ppi arithmetic before copying the result into another calculation.
Limitations
Common mistakes to avoid
- PPI describes pixels in an image or display; printer DPI can describe physical dots and is not always interchangeable.
- Round the output to a precision justified by the original measurement.
- Verify safety-critical, regulated, laboratory, and contractual conversions against the controlling standard.
Sources and further reading
These references explain the underlying standards or provide authoritative context. Your own contract, institution, clinician, product documentation, local code, or governing standard may be the controlling source.
Guidance on unit names, symbols, conversions, and numerical presentation.
Questions about this calculation
How do I convert Dots per inch to Pixels per inch?
result = input × 1 ÷ 1. Input is in dpi; result is in ppi. 1 dpi = 1 ppi. The displayed digits may be rounded.
What is 1 dpi in ppi?
1 dpi = 1 ppi. The displayed digits may be rounded.
Can I reverse the dpi to ppi conversion?
Yes. Swap the source and target units in the converter. The reverse relationship converts ppi back to dpi.
Is the Dots per inch to Pixels per inch result exact?
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.