Convert Pound-force Seconds per Square Foot to lb/(ft·s)

Formula

lb/(ft·s) = lbf·s/ft² × 32.17404855643

Derivation from SI units:

• 1 lbf·s/ft² = 4.4482216152605 N·s ÷ 0.09290304 m² = 47.880258980 Pa·s
• 1 lb/(ft·s) = 0.45359237 kg ÷ (0.3048 m × 1 s) = 1.4881639436 Pa·s
• 1 lbf·s/ft² = 47.88025898034 Pa·s ÷ 1.48816394357 Pa·s per lb/(ft·s) = 32.17404855643 lb/(ft·s)

Both units are defined exactly, so the factor is exact. Pound-force Second per Square Foot definition: pound-force second per square foot; Pound per Foot-second definition: pound per foot-second.

Worked examples

1. A reading of 0.0000209 lbf·s/ft² converts to 0.0006724376148 lb/(ft·s).
   0.0000209 lbf·s/ft² × 32.17404856 = 0.0006724376148 lb/(ft·s)
2. A value of 0.01 lbf·s/ft² is 0.3217404856 lb/(ft·s).
   0.01 lbf·s/ft² × 32.17404856 = 0.3217404856 lb/(ft·s)

Where it's used

Pound-force Seconds per Square Foot are used for US fluid-mechanics textbooks and hydraulics, while pounds per foot-second appear in heat-transfer and chemical-engineering correlations in US units. Both measure dynamic (absolute) viscosity, so the conversion is a fixed factor.

Pound-force Second per Square Foot to other dynamic viscosity 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, "pound-force second per square foot".
• 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, "pound per foot second".

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