Use our free Inches to Millimeters Converter to convert between inches (in) and millimeters (mm) instantly. Perfect for everyday use in DIY projects, engineering, and design, this converter supports both single-value and bulk conversions for quick accuracy.
It’s simple, mobile-friendly, and perfect for daily measurement tasks.
Inches ⇄ Millimeters Converter
How to Use the Inches ⇄ Millimeters Converter
- Choose the conversion direction – Inches → Millimeters or Millimeters → Inches.
- Enter a single number or paste multiple values separated by commas, spaces, or lines.
- Select how many decimal places you want the result rounded to.
- Click Swap Direction to reverse the conversion.
- Copy results easily with the Copy Results button.
Formula:
- 1 inch = 25.4 millimeters
- 1 millimeter = 0.03937 inches
Why Use This Inches to mm Converter
✔ Instant, accurate conversions
✔ Convert one or multiple values at once
✔ Adjustable rounding precision (0–6 decimals)
✔ Clean design that works on any device
✔ Perfect for builders, students, and engineers
Example Conversions
| Inches (in) | Millimeters (mm) |
|---|---|
| 1 in | 25.4 mm |
| 2.5 in | 63.5 mm |
| 6 in | 152.4 mm |
| 12 in | 304.8 mm |
| Millimeters (mm) | Inches (in) |
|---|---|
| 10 mm | 0.3937 in |
| 25 mm | 0.9843 in |
| 50 mm | 1.9685 in |
| 100 mm | 3.937 in |
FAQ
Q: Can I convert multiple numbers at once?
A: Yes — paste several numbers into the bulk field and see all results instantly.
Q: Is this converter accurate?
A: Absolutely. It uses the exact ratio of 1 inch = 25.4 mm.
Q: Can I use it on my phone?
A: Yes. It’s optimized for all devices and screen sizes.
Q: How many decimal places can I use?
A: You can select anywhere from 0 to 6 decimals for rounding precision.