Didot to Millimeter Converter

How it is calculated

The tool multiplies the size in Didot points by fixed factors: mm = D × 0.376065 and in = D × 0.01480571, where D is the size in Didot points. Millimetres are shown with two decimals and inches with four. Zero is accepted and gives 0.00 mm. A negative value, text, or a number with thousands separators such as 1,000.5 gives no result. A single comma with no dot is read as a decimal comma, so 10,5 and 10.5 are the same input. This is the Didot point of continental European typography, not the 1/72-inch DTP point (0.3528 mm) used in most software, so the two must not be mixed. Twelve Didot points make one cicero.

Common mistakes

• Treating a Didot point as the same as a DTP/PostScript point. A Didot is about 6.6% larger, so a 12 Didot size is not 12 pt.
• Confusing the cicero with the Didot point: one cicero is 12 Didot points, so enter 12, not 1, for a cicero.
• Typing a thousands separator (1,000.5) or a unit after the number; that input returns no result. Type a plain number.
• Rounding the millimetre figure and then converting again; use the four-decimal inch value or the unrounded factor when you chain calculations.