A4 to Letter Converter
Convert A4 (A4) to Letter (Letter) instantly. 1 A4 = 1 Letter.
Paper Size Converter
2 units available
1 A4 = 1 Letter
Formula:
Letter = A4 × 1With your value: 1 A4 = 1 Letter
Other A4 to Letter conversions
A4 to Letter Conversion Table
| A4 (A4) | Letter (Letter) |
|---|---|
| 0.5 | 0.5 |
| 1 | 1 |
| 2 | 2 |
| 5 | 5 |
| 10 | 10 |
| 15 | 15 |
| 20 | 20 |
| 25 | 25 |
| 50 | 50 |
| 100 | 100 |
| 250 | 250 |
| 500 | 500 |
| 1000 | 1,000 |
Letter to A4 Conversion Table
| Letter (Letter) | A4 (A4) |
|---|---|
| 0.5 | 0.5 |
| 1 | 1 |
| 2 | 2 |
| 5 | 5 |
| 10 | 10 |
| 15 | 15 |
| 20 | 20 |
| 25 | 25 |
| 50 | 50 |
| 100 | 100 |
| 250 | 250 |
| 500 | 500 |
| 1000 | 1,000 |
Where these values come from
Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.
A4 (A4)
Paper Size
ISO 216 A/B series sizes are defined by a 1:√2 aspect ratio with A0 at one square metre. North American sizes are statutory inch dimensions.
Source: ISO 216:2007, Writing paper and certain classes of printed matter — Trimmed sizes
International Organization for Standardization · Reviewed 2026-07-01
Letter (Letter)
Paper Size
ISO 216 A/B series sizes are defined by a 1:√2 aspect ratio with A0 at one square metre. North American sizes are statutory inch dimensions.
Source: ISO 216:2007, Writing paper and certain classes of printed matter — Trimmed sizes
International Organization for Standardization · Reviewed 2026-07-01
How to Convert A4 to Letter
To convert from A4 (A4) to Letter (Letter), multiply the value by 1.
Formula: Letter = A4 × 1
Reverse: A4 = Letter × 1
Step-by-Step Example
- Start with your value in A4. For example: 5 A4
- Multiply by the conversion factor: 5 x 1
- The result is: 5 Letter
About A4
The a4 (A4) is a unit of paper sizing. One a4 equals 1 millimetre of sheet width. UnitConvertLab converts it against every other paper size unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.
Common uses: paper size calculations, engineering and science, education.
About Letter
The letter (Letter) is a unit of paper sizing. One letter equals 1 millimetre of sheet width. UnitConvertLab converts it against every other paper size unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.
Common uses: paper size calculations, engineering and science, education.
Frequently Asked Questions
How many Letter are in 1 A4?
There are exactly 1 Letter in 1 A4. This means the conversion factor from A4 to Letter is 1.
What is the formula to convert A4 to Letter?
The formula to convert A4 to Letter is: Letter = A4 × 1. For example, to convert 10 A4 to Letter, you would multiply 10 by 1.
What is a A4?
The a4 (A4) is a unit of paper sizing. One a4 equals 1 millimetre of sheet width. UnitConvertLab converts it against every other paper size unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.
What is a Letter?
The letter (Letter) is a unit of paper sizing. One letter equals 1 millimetre of sheet width. UnitConvertLab converts it against every other paper size unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.
What are the common uses of A4?
The A4 is commonly used in paper size calculations, engineering and science, education.
Related Paper Size Conversions
Cite this page
UnitConvertLab. (2026). A4 to Letter converter. UnitConvertLab. Retrieved from https://unitconvertlab.com/convert/paper_a4-to-paper_letter