D series paper sizes: the forgotten ones
The D series sat alongside A, B and C in the first version of the German standard DIN 476 in 1922. It is no longer standardised today. D0 measures 771 × 1091 mm, D10 just 24 × 34 mm.
Contents of this page
All D series sizes
| Size | mm | cm | inches | Area |
|---|---|---|---|---|
| D0 | 771 × 1091 mm | 77.1 × 109.1 cm | 30.35 × 42.95 in | 0.8412 m² |
| D1 | 545 × 771 mm | 54.5 × 77.1 cm | 21.46 × 30.35 in | 0.4202 m² |
| D2 | 385 × 545 mm | 38.5 × 54.5 cm | 15.16 × 21.46 in | 0.2098 m² |
| D3 | 272 × 385 mm | 27.2 × 38.5 cm | 10.71 × 15.16 in | 0.1047 m² |
| D4 | 192 × 272 mm | 19.2 × 27.2 cm | 7.56 × 10.71 in | 0.0522 m² |
| D5 | 136 × 192 mm | 13.6 × 19.2 cm | 5.35 × 7.56 in | 0.0261 m² |
| D6 | 96 × 136 mm | 9.6 × 13.6 cm | 3.78 × 5.35 in | 0.0131 m² |
| D7 | 68 × 96 mm | 6.8 × 9.6 cm | 2.68 × 3.78 in | 0.0065 m² |
| D8 | 48 × 68 mm | 4.8 × 6.8 cm | 1.89 × 2.68 in | 0.0033 m² |
| D9 | 34 × 48 mm | 3.4 × 4.8 cm | 1.34 × 1.89 in | 0.0016 m² |
| D10 | 24 × 34 mm | 2.4 × 3.4 cm | 0.94 × 1.34 in | 0.0008 m² |
How the D series is calculated
Each D size is the geometric mean of the A size with the same number and the B size with the next number up. D0 therefore sits between A0 (841 × 1189 mm) and B1 (707 × 1000 mm), and D4 between A4 and B5. The area of D0 is 0.841 m². A curious detail: that is the same number as the short side of A0 in metres, because both are the fourth root of ½.
As in every series, the next size down is made by halving the long side. All D sizes therefore share the 1 : √2 aspect ratio and scale to A or B sizes without distortion.
Four series, one even staircase
Only with the D series do the four series form an even staircase. Sort all sizes by area and each side grows by the same factor from step to step, the eighth root of 2, about 9 %. The area grows by the fourth root of 2, about 19 %.
| Size | mm | Short side against the step before |
|---|---|---|
| B2 | 500 × 707 mm | |
| D1 | 545 × 771 mm | × 1.09 |
| A1 | 594 × 841 mm | × 1.09 |
| C1 | 648 × 917 mm | × 1.091 |
| B1 | 707 × 1000 mm | × 1.091 |
| D0 | 771 × 1091 mm | × 1.091 |
| A0 | 841 × 1189 mm | × 1.091 |
| C0 | 917 × 1297 mm | × 1.09 |
| B0 | 1000 × 1414 mm | × 1.091 |
With only A, B and C, the step between B(n) and A(n−1) is twice as big as all the others. That is exactly where the D size sits. Mathematically elegant, but it never caught on.
Why the D series disappeared
The D series never found a job of its own. A covered letters, exercise books and files, C covered envelopes and B covered posters and books. Today's standards, ISO 216 for A and B and the German DIN 476-2 for C, no longer include it. More on how the standards came about in the history of paper sizes.
Not to be confused with the Swedish D series
The Swedish standard SIS 01 47 11, since withdrawn, added its own D, E, F and G series. Its D series has nothing to do with the German one: Swedish D0 measures 1091 × 1542 mm. Its short side is as long as the long side of German D0. If you come across a D size, always check the millimetres.
Everyday coincidences
- D5 at 136 × 192 mm is almost exactly a DVD case (about 135 × 190 mm).
- D9 at 34 × 48 mm is close to a 35 × 45 mm passport photo.
- D4 at 192 × 272 mm is an A4 sheet with a narrow border trimmed off.
- D7 at 68 × 96 mm is a little larger than a poker card.
Frequently asked questions
Does the D paper series still exist?
No. The D series was part of the first German DIN 476 of 1922 and is no longer standardised.
How big is D0?
771 × 1091 mm, with an area of 0.841 m².
How big is D4?
192 × 272 mm, slightly smaller than A4 (210 × 297 mm).
How is the D series calculated?
Each D size is the geometric mean of the A size with the same number and the B size with the next number up.
Is the Swedish D series the same?
No. Swedish D0 from SIS 01 47 11 measures 1091 × 1542 mm and is much larger.