Inches per Year to Millimetres per Year (ipy to mm/y)
1 inch per year (ipy) = 25.4 millimetres per year (mm/y). 1 mm/y = 0.03937007874 ipy. Example: 15 ipy = 15 × 25.4 = 381 mm/y.
Also searched as inches per year to mm/y, inches per year in mm/y, inches per year into millimetres per year, ipy to mm/y, ipy in millimetres per year, ipy into millimetre per year, inch per year to millimetre per year, ipy to millimetres per year converter, inches per year to millimeters per year and how many millimetres per year in an inch per year.
1 ipy = 25.4 mm/y
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk inch per year to millimetre per year converter to paste a column from Excel.
How to Convert Inch per Year to Millimetre per Year
- 1 ipy = 25.4 mm/y
- 1 mm/y = 0.03937007874 ipy
- Example: convert 15 ipy to mm/y: 15 ipy = 15 × 25.4 mm/y = 381 mm/y
Formula
mm/y = ipy × 25.4
Derivation from SI units:
- 1 ipy = 25.4 mm/y = 1000 mpy (exact)
- Thickness loss in millimetres per year of exposure (the reference unit for corrosion rate)
Both units are defined exactly, so the factor is exact. Inch per Year definition: inch per year; Millimetre per Year definition: millimetre per year.
Worked examples
- A reading of 0.002 ipy converts to 0.0508 mm/y.
0.002 ipy × 25.4 = 0.0508 mm/y - A value of 0.02 ipy is 0.508 mm/y.
0.02 ipy × 25.4 = 0.508 mm/y
Inch per Year to Millimetre per Year conversion table
| Inches per Year (ipy) | Millimetres per Year (mm/y) |
|---|---|
| 0.0001 ipy | 0.00254 mm/y |
| 0.0005 ipy | 0.0127 mm/y |
| 0.001 ipy | 0.0254 mm/y |
| 0.002 ipy | 0.0508 mm/y |
| 0.005 ipy | 0.127 mm/y |
| 0.01 ipy | 0.254 mm/y |
| 0.02 ipy | 0.508 mm/y |
| 0.05 ipy | 1.27 mm/y |
| 0.1 ipy | 2.54 mm/y |
| 0.5 ipy | 12.7 mm/y |
Where it's used
Inches per Year are used for older corrosion resistance tables, while millimetres per year appear in corrosion coupon and weight-loss tests. Both measure corrosion rate (thickness loss per year), so the conversion is a fixed factor.
Inch per Year to other corrosion rate units
| Conversion | 1 ipy equals |
|---|---|
| inch per year to millimetre per year | 25.4 mm/y |
| inch per year to mil per year | 1000 mpy |
| inch per year to micrometre per year | 25400 µm/y |
Frequently asked questions
How many millimetres per year are in 1 inch per year?
1 ipy = 25.4 mm/y.
How do I convert inches per year to millimetres per year?
Multiply the value in ipy by 25.4. For example, 15 ipy × 25.4 = 381 mm/y.
Is the ipy to mm/y conversion exact?
Yes. Both units are defined exactly, and 1 ipy is exactly 25.4 mm/y.
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "inch".
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology .
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Inches per Year to Millimetres per Year (ipy to mm/y). Retrieved October 25, 2026, from https://scientificconverters.com/corrosion-rate/inches-per-year-to-millimeters-per-year/
IEEE
Scientific Converters, "Inches per Year to Millimetres per Year (ipy to mm/y)," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/corrosion-rate/inches-per-year-to-millimeters-per-year/