Convert Inches of Water (60 °F) to Inches of Mercury

Formula

inHg = inH₂O (60 °F) × 0.07348241044623

or inHg = inH₂O (60 °F) ÷ 13.60869892437

Derivation from SI units:

• 1 inH₂O (60 °F) ≈ 999.0 kg/m³ × 9.80665 m/s² × 0.0254 m ≈ 248.84 Pa
• 1 inHg = 13 595.1 kg/m³ × 9.80665 m/s² × 0.0254 m = 3386.388640341 Pa
• 1 inH₂O (60 °F) = 248.84 Pa ÷ 3386.388640341 Pa per inHg = 0.07348241044623 inHg

One unit is a measured value, so the factor is approximate. Inch of Water (60 °F) definition: inch of water (60 °F); Inch of Mercury definition: inch of mercury.

Worked examples

1. A reading of 0.5 inH₂O (60 °F) converts to 0.03674120522 inHg.
   0.5 inH₂O (60 °F) × 0.07348241045 = 0.03674120522 inHg
2. A value of 7 inH₂O (60 °F) is 0.5143768731 inHg.
   7 inH₂O (60 °F) × 0.07348241045 = 0.5143768731 inHg

Where it's used

Inches of Water (60 °F) are used for older US gas-industry and flow-meter references, while inches of mercury appear in aircraft altimeter settings (standard 29.92 inHg). Both measure pressure, stress and differential pressure (force per unit area), so the conversion is a fixed factor.

Inch of Water (60 °F) to other pressure units

Frequently asked questions

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 of water (60 °F)".
• 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 of mercury, conventional (inHg)".

Last reviewed: 2026-10-15. Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.