What is the inches-to-pixels formula?

Pixels equal inches multiplied by pixels per inch. An 8.5 inch side at 300 PPI is 8.5 times 300, or 2550 pixels. You need both the physical size and resolution to get a pixel count.

Should I use 96 or 300 pixels per inch?

Use the resolution required by your intended output. At 96 PPI one inch corresponds to 96 pixels; at 300 PPI it corresponds to 300. The 96 value is a CSS layout convention, not a measurement of your monitor. A print provider may specify 300 PPI or another resolution for the chosen size and viewing distance.

How many pixels are 4 by 6 and 8.5 by 11 inch prints?

At 300 PPI, 4 by 6 inches is 1200 by 1800 pixels, and 8.5 by 11 inches is 2550 by 3300. At 150 PPI the counts are 600 by 900 and 1275 by 1650. Type the size and resolution needed for your job; these examples do not set a universal print requirement.

What if the answer is not a whole number of pixels?

Image dimensions use whole pixels. The calculator rounds to the nearest whole pixel and shows the unrounded result beside the working. For example, 1.234 inches at 96 PPI is 118.464 pixels, shown as 118 pixels.

Will this resize my image or change its DPI?

This page calculates dimensions only. Use Image Resizer for the actual pixel dimensions, then Image DPI Changer if you need resolution metadata in a JPEG or PNG. Enlarging an image interpolates existing pixels and does not recover missing detail.

Can I convert centimetres, millimetres or pixels instead?

Yes. Change the unit to Centimetres or Millimetres to calculate the pixel dimensions from a metric size. Switch to Pixels to size to calculate physical size from an existing pixel count. The chosen resolution is required in either direction.

Inches to Pixels

Enter the width and height you want in inches and the number of pixels per inch. This page opens in Size to pixels mode with an 8.5 by 11 inch example at 300 PPI: 2550 by 3300 pixels. Change any value, or clear the height to convert one side. The table compares common resolutions, and fractional pixel results are rounded to whole pixels with the working shown.

PIXEL SIZE

2550 x 3300 px

8.5 x 11 in at 300 DPI · 21.59 x 27.94 cm

Pixels: 2550 x 3300
DPI: 300
Inches: 8.5 x 11
Centimetres: 21.59 x 27.94

Width: 8.5 in times 300 DPI is 2550 px.
Height: 11 in times 300 DPI is 3300 px.
Nothing above is rounded: that size lands on whole pixels at 300 DPI.
One inch is 25.4 mm exactly, so the inch, centimetre and millimetre figures are one measurement written three ways.
A pixel has no size until something prints or displays it, so every figure here follows from the 300 DPI you entered. DPI and PPI mean the same number in this arithmetic.

The numbers you have

Enter the size you want on paper and the resolution, and the pixel count follows. One side is enough: leave the height empty and the width is converted on its own.

Direction

Width in inHeight in inResolution in DPIUnit

Common resolutions: 300 for photo printing, 150 for a poster read at arm's length, 72 or 96 for a screen mock-up. DPI and PPI mean the same number here.

The same job at every common resolution

The size on paper stays as you typed it and the pixel count moves. The row you are on is marked.

2550 x 3300 px and 8.5 x 11 in, row by row
Resolution	Pixels	Inches	Centimetres
72 DPI	612 x 792	8.5 x 11	21.59 x 27.94
96 DPI	816 x 1056	8.5 x 11	21.59 x 27.94
150 DPI	1275 x 1650	8.5 x 11	21.59 x 27.94
200 DPI	1700 x 2200	8.5 x 11	21.59 x 27.94
240 DPI	2040 x 2640	8.5 x 11	21.59 x 27.94
300 DPI	2550 x 3300	8.5 x 11	21.59 x 27.94
600 DPI	5100 x 6600	8.5 x 11	21.59 x 27.94

Worked both ways

The three conversions below run through the very same functions as the answer above them.

2480 x 3508 at 300to inches
8.27 x 11.69
8 x 10 in at 300to pixels
2400 x 3000
Same pixels at 72to inches
34.44 x 48.72

Accuracy. Exact arithmetic: pixels divided by the resolution you enter, both directions on the same page. The resolution is yours to set because a pixel has no physical size of its own until something prints it.

Common questions

What is the inches-to-pixels formula?: Pixels equal inches multiplied by pixels per inch. An 8.5 inch side at 300 PPI is 8.5 times 300, or 2550 pixels. You need both the physical size and resolution to get a pixel count.
Should I use 96 or 300 pixels per inch?: Use the resolution required by your intended output. At 96 PPI one inch corresponds to 96 pixels; at 300 PPI it corresponds to 300. The 96 value is a CSS layout convention, not a measurement of your monitor. A print provider may specify 300 PPI or another resolution for the chosen size and viewing distance.
How many pixels are 4 by 6 and 8.5 by 11 inch prints?: At 300 PPI, 4 by 6 inches is 1200 by 1800 pixels, and 8.5 by 11 inches is 2550 by 3300. At 150 PPI the counts are 600 by 900 and 1275 by 1650. Type the size and resolution needed for your job; these examples do not set a universal print requirement.
What if the answer is not a whole number of pixels?: Image dimensions use whole pixels. The calculator rounds to the nearest whole pixel and shows the unrounded result beside the working. For example, 1.234 inches at 96 PPI is 118.464 pixels, shown as 118 pixels.
Will this resize my image or change its DPI?: This page calculates dimensions only. Use Image Resizer for the actual pixel dimensions, then Image DPI Changer if you need resolution metadata in a JPEG or PNG. Enlarging an image interpolates existing pixels and does not recover missing detail.
Can I convert centimetres, millimetres or pixels instead?: Yes. Change the unit to Centimetres or Millimetres to calculate the pixel dimensions from a metric size. Switch to Pixels to size to calculate physical size from an existing pixel count. The chosen resolution is required in either direction.

Exact arithmetic: pixels divided by the resolution you enter, both directions on the same page. The resolution is yours to set because a pixel has no physical size of its own until something prints it.