The standard US post card size is 4×6 inches. Learn all standard postcard sizes, USPS mailing size requirements, pixel dimensions for printing, and how 4×6 compares to 5×7 and 6×9.
| Size name | Inches (W × H) | mm (W × H) | 300 DPI pixels | USPS rate | Best use |
|---|---|---|---|---|---|
| 4×6 Standard | 4.000 × 6.000 | 101.6 × 152.4 | 1200 × 1800 | Postcard rate | Personal mail, marketing, photos |
| 4.25×5.5 Small | 4.250 × 5.500 | 108.0 × 139.7 | 1275 × 1650 | Postcard rate | Coupons, announcements |
| 4.25×6 (max postcard) | 4.250 × 6.000 | 108.0 × 152.4 | 1275 × 1800 | Postcard rate | Largest size at postcard rate |
| 5×7 Large | 5.000 × 7.000 | 127.0 × 177.8 | 1500 × 2100 | First-Class | Bold marketing, real estate |
| 6×9 Jumbo | 6.000 × 9.000 | 152.4 × 228.6 | 1800 × 2700 | First-Class | EDDM campaigns, maximum impact |
| 6×11 Panoramic | 6.000 × 11.000 | 152.4 × 279.4 | 1800 × 3300 | First-Class | EDDM, high-visibility campaigns |
| A6 (EU standard) | 4.133 × 5.827 | 105.0 × 148.0 | 1240 × 1748 | EU postal | International / European mail |
| A5 (EU large) | 5.827 × 8.268 | 148.0 × 210.0 | 1748 × 2480 | EU postal | Large format EU postcards |
| DL (EU slim) | 3.898 × 8.661 | 99.0 × 220.0 | 1169 × 2598 | EU postal | Slim promotional cards, vouchers |
The 4×6-inch postcard became the de facto US standard because it fits neatly within the USPS postcard rate size window (max 4.25×6 inches) while providing enough space for a photograph, graphic, and mailing information on the back. It also matches the standard 4×6 photo print size, which makes it easy to produce at photo labs, office printers, and commercial offset shops.
When people ask about the "average" or "typical" postcard size, they almost always mean the 4×6-inch standard. For marketing mail, 5×7 inches is also very common — it is larger than the competition in the mailbox and still affordable to print and mail. For EDDM (Every Door Direct Mail) campaigns, 6×9 and 6×11 inches are the dominant formats because their large surface area maximizes visibility without requiring a mailing list.
For a 4×6-inch postcard, your print file should be set up as:
USPS offers a reduced "postcard rate" for cards that are 3.5–4.25 inches tall and 5–6 inches wide with a thickness of 0.007–0.016 inches. The standard 4×6 postcard qualifies. Cards larger than 4.25×6 inches — including 5×7, 6×9, and 6×11 — are mailed at the First-Class letter rate, which is slightly higher. For bulk campaigns, EDDM lets you mail any of these sizes at a reduced flat rate without individual addressing.
Postcard paper (heavy cardstock for printing postcards at home) is sold in 4×6 inch sheets (single cards) and in 8.5×11 letter sheets with two 4×5.5-inch postcards per sheet. Avery, Neenah, and other brands sell perforated letter-size postcard sheets that print in a standard home printer and then tear apart at the perforations.
USPS requires postcards to be at least 0.007 inches thick. A 90–110 lb cover stock (243–298 gsm) is the typical range for printed postcards. Most commercial printers use 14 pt or 16 pt cardstock (0.014–0.016 inches), which is stiff, premium-feel, and stays within USPS thickness limits. Anything thinner than 0.007 inches will not qualify for the postcard rate.
At 300 DPI, a 4×6-inch postcard trim is 1200 × 1800 pixels. With the 0.125-inch bleed added on all sides (4.25 × 6.25 inches), the bleed canvas is 1275 × 1875 pixels. Always design at the bleed size and set your printer's trim marks at the 4×6 boundary.
Yes, but it will not meet USPS thickness requirements (0.007" minimum) if you use standard 20 lb / 75 gsm copy paper (about 0.004 inches thick). For mailing, use cardstock of at least 80 lb cover / 216 gsm. For non-mailed cards (handouts, table tents, gifts), any paper weight works fine.
A 4×6 postcard qualifies for the lower USPS postcard rate, is cheaper to print, and fits the standard 4×6 photo format. A 5×7 postcard is larger, stands out more in the mail, and is better for marketing campaigns where visibility matters — but it requires a First-Class letter stamp. The price difference in postage per piece is typically $0.10–0.20 (2026 rates).