What is the A4 paper size?

A4 = 210×297mm = 8.27×11.69 inches. Most common paper size worldwide for documents and printing.

Is this conversion mathematically exact?

Yes, this converter uses precise conversion factors based on international standards. Results are accurate to the displayed precision.

Can I use this for professional applications?

This converter is suitable for educational and general purposes. For critical professional applications, always verify with authoritative sources.

ISO A-Series Paper Sizes Paper Size Converter - Free Online

Free online iso a-series paper sizes with dimensions in multiple units.

Compare international paper standards and find the right size for your needs.

Show this tool on your website

Last updatedMay 21, 2026How we build & check our tools

This calculator requires JavaScript to function. Please enable JavaScript in your browser to use all features.

Frequently Asked Questions

Common questions about the ISO A-Series Paper Sizes Paper Size Converter - Free Online

ISO 216 standard. A0: 1m² area. Each size half the previous: A1, A2, A3, A4, etc. Same aspect ratio.

Learn More

Sources & References

ISO 216 paper sizes (A, B series)

The international standard defining A- and B-series paper dimensions (e.g., A4 = 210 × 297 mm).

→Source: ISO 216 — Writing paper and certain classes of printed matter

Explore More Tools

Continue your financial journey with these related calculators

paper-sizes

Envelope Size Converter

Free online paper sizes unit converter. Convert between all paper sizes units instantly with accurate results, formulas, and reference tables. No signup required.

Try it now

paper-sizes

Photo Size Converter

Free online paper sizes unit converter. Convert between all paper sizes units instantly with accurate results, formulas, and reference tables. No signup required.

Try it now

paper-sizes

Poster Size Converter

Free online paper sizes unit converter. Convert between all paper sizes units instantly with accurate results, formulas, and reference tables. No signup required.

Try it now

paper-sizes

Business Card Size Paper Size Converter - Free Online

Convert business card size paper size values instantly with our free tool. Get accurate results with clear explanations.

Try it now

paper-sizes

Canvas Size Converter

Free online paper sizes unit converter. Convert between all paper sizes units instantly with accurate results, formulas, and reference tables. No signup required.

Try it now

paper-sizes

Paper Size Converter

Free online paper size converter with dimensions in multiple units. Compare international paper standards and find the right size for your needs.

Try it now