Cubic feet per minute to US gallons per minute Calculator

Direct answer

Multiply the entered cubic feet per minute value by 7.48051948051948 to express it in us gallons per minute (gpm). This converts cubic foot per minute (cfm) to US gallon per minute (gpm) within the documented flow rate family.

Variables and formula

• Cubic feet per minute (cfm): the source value measured in cubic foot per minute.
• US gallons per minute (gpm): the same quantity expressed in US gallon per minute.
• Conversion factor: 7.48051948051948 us gallons per minute per cubic foot per minute.

US gallons per minute = Cubic feet per minute × 7.48051948051948

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: cubic foot per minute (cfm). One cubic international foot per minute equals exactly 28.316846592 litres per minute. Named variant used: International-foot volume; actual volumetric flow unless another condition is explicitly stated. Reference: National Institute of Standards and Technology: NIST Guide to the SI, Appendix B.9: Factors for Units Listed by Kind of Quantity or Field of Science; National Institute of Standards and Technology: NIST Handbook 44 (2026), Appendix C: General Tables of Units of Measurement.

Target unit: US gallon per minute (gpm). One U.S. liquid gallon per minute equals exactly 3.785411784 litres per minute because the U.S. gallon is exactly 231 international cubic inches. Named variant used: U.S. liquid gallon only; not Imperial gallon. Reference: National Institute of Standards and Technology: NIST Guide to the SI, Appendix B.9: Factors for Units Listed by Kind of Quantity or Field of Science; National Institute of Standards and Technology: NIST Handbook 44 (2026), Appendix C: General Tables of Units of Measurement.

The cfm-to-gpm direction remains inside the flow rate quantity; it changes the unit label and numerical scale, not the kind of quantity being measured.

Relationship and precision

The named unit relationships are defined or exact, so the conversion is exact before display rounding and source-measurement uncertainty.

• cfm relationship: The terminating factor is exact because the international foot is exactly 0.3048 m and the litre is exactly 10^-3 m³.
• gpm relationship: The terminating base factor is exact for the U.S. liquid gallon and international inch.

To audit the factor through the family base unit, divide the raw dataset factors 28.316846592 by 3.785411784. The generator emits that quotient once at 15 significant digits as the canonical direct factor 7.48051948051948; runtime calculations do not divide the already-emitted base factors again.

Reproducible example

For 10 cubic feet per minute, 10 × 7.48051948051948 = 74.8051948051948 us gallons per minute. Repeating the same multiplication with the stated factor reproduces the displayed conversion before interface rounding.

Directional scale check

Because one cubic foot per minute contains 7.48051948051948 us gallons per minute, 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 us gallons per minute, not cubic feet per minute. A value entered as cfm leaves the calculator labelled gpm; this directional distinction matters even when the two units describe the same flow rate quantity.

Assumptions and limitations

• Only non-negative flow magnitudes are accepted; direction is outside this family.
• Gas flows quoted at standard or actual conditions require temperature and pressure normalization that this unit-only converter does not perform.
• A conversion does not add significant figures to the source measurement.

Common mistakes

• Do not use a legacy survey-foot volume.
• Imperial gpm uses a different gallon and must not use this factor.

Continue within the Flow Rate family

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

• Reverse the direction: US gallons per minute to Cubic feet per minute
• Compare another flow rate route: Cubic feet per minute to Liters per minute
• Compare another flow rate route: Cubic feet per minute to Liters per second
• Compare another flow rate route: Cubic feet per minute to Cubic meters per hour
• Compare another flow rate route: US gallons per minute to Liters per minute

Assumptions

• The entered value uses cubic feet per minute exactly as labelled.
• Only non-negative flow magnitudes are accepted; direction is outside 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.9: Factors for Units Listed by Kind of Quantity or Field of Science; 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