Pounds per US gallon to Pounds per cubic foot Calculator

Direct answer

Multiply the entered pounds per us gallon value by 7.48051948046357 to express it in pounds per cubic foot (lb/ft³). This converts pound per US gallon (lb/US gal) to pound per cubic foot (lb/ft³) within the documented density family.

Variables and formula

• Pounds per US gallon (lb/US gal): the source value measured in pound per US gallon.
• Pounds per cubic foot (lb/ft³): the same quantity expressed in pound per cubic foot.
• Conversion factor: 7.48051948046357 pounds per cubic foot per pound per US gallon.

Pounds per cubic foot = Pounds per US gallon × 7.48051948046357

The generator emits numeric factors with at most 15 significant digits. Calculator results keep up to 10 significant digits for display; this formatting does not increase the precision of the measurement.

Unit definitions and named variants

Source unit: pound per US gallon (lb/US gal). This unit uses one avoirdupois pound per U.S. liquid gallon, where 1 U.S. gal = 231 in³ = 0.003785411784 m³ exactly. Named variant used: U.S. liquid gallon only; not the British Imperial gallon. Reference: National Institute of Standards and Technology: NIST Guide to the SI, Appendix B.8: Factors for Units Listed Alphabetically; National Institute of Standards and Technology: NIST Handbook 44 (2026), Appendix C: General Tables of Units of Measurement.

Target unit: pound per cubic foot (lb/ft³). This unit uses one avoirdupois pound per cubic international foot; its exact-reference conversion begins 16.018463373960139… kg/m³. Named variant used: Avoirdupois pound per cubic international foot; not pound-force or survey-foot volume. Reference: National Institute of Standards and Technology: NIST Guide to the SI, Appendix B.8: Factors for Units Listed Alphabetically; National Institute of Standards and Technology: NIST Handbook 44 (2026), Appendix C: General Tables of Units of Measurement.

The lb/US gal-to-lb/ft³ direction remains inside the density quantity; it changes the unit label and numerical scale, not the kind of quantity being measured.

Relationship and precision

This route uses at least one deliberately preserved rounded factor. Treat the displayed factor as an approximation at the precision documented below.

• lb/US gal relationship: The preserved application factor is truncated relative to the exact-reference quotient 119.8264273168966… kg/m³; this discrepancy is documented rather than silently changing the generator factor.
• lb/ft³ relationship: The preserved application factor is a rounded decimal of the exact value derived from 0.45359237 kg and (0.3048 m)³.

To audit the factor through the family base unit, divide the raw dataset factors 119.826427316 by 16.01846337396. The generator emits that quotient once at 15 significant digits as the canonical direct factor 7.48051948046357; runtime calculations do not divide the already-emitted base factors again.

Reproducible example

For 10 pounds per us gallon, 10 × 7.48051948046357 = 74.8051948046357 pounds per cubic foot. Repeating the same multiplication with the stated factor reproduces the displayed conversion before interface rounding.

Directional scale check

Because one pound per US gallon contains 7.48051948046357 pounds per cubic foot, the target number is larger than the source number for every positive input. Zero maps to zero, while negative inputs are rejected because this family models non-negative magnitudes.

Interpretation

Read the result as pounds per cubic foot, not pounds per us gallon. A value entered as lb/US gal leaves the calculator labelled lb/ft³; this directional distinction matters even when the two units describe the same density quantity.

Assumptions and limitations

• Only non-negative mass-density magnitudes are accepted by this family.
• This family covers mass density only; it does not convert relative density, specific gravity, number density, or weight density.
• Pound per US gallon means avoirdupois pounds per U.S. liquid gallon of exactly 231 cubic inches, not an Imperial gallon.

Common mistakes

• lb denotes avoirdupois pound mass, not pound-force.
• lb denotes pound mass here, not lbf.

Continue within the Density family

See the Density conversion hub for its five-unit reference table and all 20 directed routes.

• Reverse the direction: Pounds per cubic foot to Pounds per US gallon
• Compare another density route: Pounds per US gallon to Kilograms per cubic meter
• Compare another density route: Pounds per US gallon to Grams per cubic centimeter
• Compare another density route: Pounds per US gallon to Kilograms per liter
• Compare another density route: Pounds per cubic foot to Kilograms per cubic meter

Assumptions

• The entered value uses pounds per us gallon exactly as labelled.
• Only non-negative mass-density magnitudes are accepted by this family.
• Rounding and measurement uncertainty remain the user's responsibility.

Sources and methodology

CalcMotive publishes the formula and assumptions so you can decide whether the estimate fits your use case. See our methodology standards.

• NIST Guide to the SI, Appendix B.8: Factors for Units Listed Alphabetically; National Institute of Standards and Technology; accessed Aug 7, 2026
• NIST Handbook 44 (2026), Appendix C: General Tables of Units of Measurement; National Institute of Standards and Technology; accessed Aug 7, 2026