Resize Image in cm

How cm becomes pixels

A centimetre is a length on paper. A picture file has no length until you say how many pixels go into one inch, and that number is the DPI. So the tool needs three things from you: a width, a height and a DPI. For each side it works out pixels = cm ÷ 2.54 × DPI, because one inch is 2.54 cm.

For 3.5 × 4.5 cm at 300 DPI: 3.5 ÷ 2.54 × 300 = 413.386, which is 413 pixels, and 4.5 ÷ 2.54 × 300 = 531.496, which is 531 pixels. The rounding is to the nearest whole pixel. A side that would come out under 16 or over 4,000 pixels is set to 16 or 4,000.

Every cell comes from the function the tool uses in centimetres mode, so what you read here is what you get. Sizes in inches were first multiplied by 2.54 and typed as cm. For a size with no row, apply the rule above to each side.

How we tested

The test picture is a computer-generated image of coloured circles, 1200 × 900 px and 285.1 KB, with no person in it. Each row is one run of this tool's own code in centimetres mode: 3.5 × 4.5 cm, fill frame, and the maximum KB the tool opens with (1,024) unless the row says otherwise. The last column is the DPI read back from the JPG header of the output.

300 DPI asks for 2.2 times the pixels of 200 DPI for the same centimetres, and the file came out 2.0 times as large. Holding the 300 DPI size to a 50 KB maximum kept every pixel and lowered the JPG quality instead.

To see whether the DPI label matters to the file, we saved the same 413 × 531 pixel picture three times with different labels.

Tested on 14 October 2026 by running this tool's own code outside the browser (a KB here is 1,000 bytes). Your own photograph and your browser will give different sizes, so treat the numbers as an example.

Sizes in cm that forms state

Each row was read in the authority's own document on 14 October 2026. The figures are as the notice prints them. The last column is what the notice does not say, which is usually the DPI. If your portal shows other figures, follow the portal.

SSC's 2026 cycles take the photograph live in the application, so the signature is the only SSC image that has a size in cm. The CHSL and CPO pages quote the 6.0 and 4.0 cm statements in full.

What the pixel counts in those notices imply

Some notices give a length and a pixel count for the same side. Dividing the pixels by the length in inches (cm ÷ 2.54) shows the DPI that would make the two agree. This is our arithmetic on their numbers, not something the notices state.

The TNPSC counts all sit near 96 DPI, while the same sections tell you to scan at 200. Taking 3.5 cm as the width, the IBPS photograph implies a different DPI for width and for height, so no single DPI turns 3.5 × 4.5 cm into 200 × 230 pixels. Only the IBPS thumb impression and declaration come close to their stated 200 DPI: 3 cm at 200 DPI is 236.2 pixels and the notice gives 240.

So when a notice gives pixels, those are the numbers to match. Use resize image in pixels for that, and keep this page for forms that give only centimetres.

Which DPI to pick when the form gives none

If the form states a DPI, use it. IBPS states 200 DPI for the thumb impression and the declaration, and TNPSC says to scan the photograph and the signature at 200 DPI. The SSC CHSL and CPO 2026 notices give the signature in centimetres in their text, and the sample upload screen printed in each notice adds “at a resolution of 300 DPI”: 6.0 × 2.0 cm at 300 DPI is 709 × 236 pixels.

If it gives only centimetres and no DPI anywhere, a DPI you choose is a working assumption, and none of the notices we read says what the upload page checks beyond the KB range. At 200 DPI a 6.0 × 2.0 cm signature is 472 × 157 pixels; at 300 DPI it is 709 × 236. The larger one has 2.3 times the pixels, so the same signature makes a larger file.

300 is the DPI this tool opens with. None of the notices above uses it. Treat it as a common choice for printing a photo, not as a rule, and lower it if your KB limit is tight. If the form also gives pixels, ignore the DPI question and match the pixels.