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ISO A Series Paper Sizes
The complete A series with dimensions in mm and inches:
Size Width × Height (mm) Width × Height (inches)
A0 841 × 1189 33.11 × 46.81
A1 594 × 841 23.39 × 33.11
A2 420 × 594 16.54 × 23.39
A3 297 × 420 11.69 × 16.54
A4 210 × 297 8.27 × 11.69
A5 148 × 210 5.83 × 8.27
A6 105 × 148 4.13 × 5.83
A7 74 × 105 2.91 × 4.13
A8 52 × 74 2.05 × 2.91
Each size is exactly half the area of the previous. A4 folded in half = A5. Two A4 sheets side by side = A3. All share the same 1:√2 (≈1:1.414) aspect ratio.
North American Paper Sizes
US and Canadian standard sizes:
Name Width × Height (inches) Width × Height (mm)
Letter 8.5 × 11 215.9 × 279.4
Legal 8.5 × 14 215.9 × 355.6
Tabloid 11 × 17 279.4 × 431.8
Ledger 17 × 11 431.8 × 279.4
Executive 7.25 × 10.5 184.2 × 266.7
Statement 5.5 × 8.5 139.7 × 215.9
Letter (8.5×11") is the US equivalent of A4. They are close in size but not identical — Letter is slightly wider and shorter than A4.
A4 vs Letter Comparison
The two most common office paper sizes worldwide:
A4 Letter
Width: 210 mm 215.9 mm (Letter is 5.9mm wider)
Height: 297 mm 279.4 mm (A4 is 17.6mm taller)
Area: 62,370 mm² 60,323 mm²
Aspect: 1:1.414 1:1.294
Scaling A4 content to Letter:
Width scale: 215.9 / 210 = 1.028 (2.8% wider)
Height scale: 279.4 / 297 = 0.941 (5.9% shorter)
→ Content will be slightly cut off at top/bottom or have margins
Paper Size in Points (PDF/Typography)
PDF documents use points as their internal unit (1 point = 1/72 inch):
Size mm Points
A4 210 × 297 595 × 842
A3 297 × 420 842 × 1191
A5 148 × 210 420 × 595
Letter 215.9 × 279.4 612 × 792
Legal 215.9 × 355.6 612 × 1008
Tabloid 279.4 × 431.8 792 × 1224
When creating PDFs programmatically, use points. An A4 PDF page is 595×842 points. These are the values used in PDF specifications and tools like PDFKit, iText, and ReportLab.
Pixel Dimensions at Different DPI
A4 paper at various print resolutions:
DPI Width (px) Height (px) Use case
72 595 842 Screen display (72 DPI = 1pt = 1px)
96 794 1123 Windows screen resolution
150 1240 1754 Low-quality print
300 2480 3508 Standard print quality
600 4961 7016 High-quality print / professional
Letter (8.5 × 11 inches) at 300 DPI:
Width: 8.5 × 300 = 2550 pixels
Height: 11 × 300 = 3300 pixels
Always design print documents at 300 DPI minimum. A document designed at 72 DPI will look blurry when printed.
Print Bleed Calculations
Adding 3mm bleed on all sides for professional printing:
A4 with 3mm bleed:
Final trim size: 210 × 297 mm
With bleed: 216 × 303 mm (add 3mm each side)
In pixels (300 DPI): 2551 × 3579 px
A4 with 5mm bleed (for large format):
With bleed: 220 × 307 mm
Letter with 0.125" bleed (standard US):
Final trim: 8.5 × 11 inches
With bleed: 8.75 × 11.25 inches
In pixels (300 DPI): 2625 × 3375 px
ISO B and C Series
B series for posters and books, C series for envelopes:
B Series (between A sizes):
B4: 250 × 353 mm (common book size)
B5: 176 × 250 mm (common book/notebook size)
B6: 125 × 176 mm (small book)
C Series (envelopes for A series paper):
C4: 229 × 324 mm → fits unfolded A4
C5: 162 × 229 mm → fits A4 folded in half (= A5)
C6: 114 × 162 mm → fits A4 folded in quarters (= A6)
DL: 110 × 220 mm → fits A4 folded in thirds (standard business envelope)
Japanese JIS Paper Sizes
Japan uses JIS B series alongside ISO A series:
JIS B4: 257 × 364 mm (slightly larger than ISO B4)
JIS B5: 182 × 257 mm (common Japanese book size)
JIS B6: 128 × 182 mm
Note: JIS B sizes are different from ISO B sizes!
ISO B5: 176 × 250 mm
JIS B5: 182 × 257 mm (6mm wider, 7mm taller)
Unit Conversion Reference
Converting between paper size units:
1 inch = 25.4 mm = 72 points = 2.54 cm
1 mm = 0.0394 inches = 2.835 points
1 point = 0.353 mm = 0.0139 inches
1 cm = 10 mm = 0.394 inches = 28.35 points
A4 width (210mm) in other units:
Centimeters: 21.0 cm
Inches: 8.268 inches
Points: 595.3 points
Pixels @96dpi: 793.7 px
Pixels @300dpi: 2480.3 px