SCFM Calculator
Convert between SCFM and ACFM using actual pressure and temperature with standard 14.7 psia and 68°F.
SCFM vs ACFM
SCFM (standard cubic feet per minute) and ACFM (actual cubic feet per minute) describe gas volumetric flow at different pressure and temperature conditions. Compressor ratings and piping calculations often require converting between them.
Conversion Formula
$$SCFM = ACFM \times \frac{P_{\text{act}}}{P_{\text{std}}} \times \frac{T_{\text{std}}}{T_{\text{act}}}$$Standard conditions use \(P_{\text{std}} = 14.7\) psia and \(T_{\text{std}} = 68°\text{F}\). Actual pressure and temperature must be in absolute units (psia and Rankine, or any consistent absolute pair).
Example: 100 ACFM at 14.7 psia and 68°F equals 100 SCFM because the correction factor is 1.0.
Why Temperature Uses Absolute Scale
The ideal gas law ratio \(T_{\text{std}}/T_{\text{act}}\) requires absolute temperature. Convert Fahrenheit to Rankine by adding 459.67. At higher actual temperature, the same mass flow occupies more volume, so SCFM is lower than ACFM.
Frequently Asked Questions
What are standard conditions for SCFM?
This calculator uses 14.7 psia and 68°F (20°C), common in US compressed-air engineering. Some industries use 14.696 psia and 60°F, check your equipment datasheet.
Why does higher temperature reduce SCFM?
Hot gas expands. The same ACFM at higher temperature represents less mass flow, so corrected SCFM decreases when \(T_{\text{act}} > T_{\text{std}}\).
Must pressure be in psia?
Yes. Gauge pressure (psig) must be converted to absolute by adding atmospheric pressure before using the ratio.
Can I convert SCFM back to ACFM?
Yes. Rearrange: \(ACFM = SCFM / [(P_{\text{act}}/P_{\text{std}})(T_{\text{std}}/T_{\text{act}})]\). Use the reverse mode in the calculator.
Related Tools
CSS Gradient Generator
Working Capital Turnover Ratio Calculator
Random Integer Range Generator
Hydrogen Ion Concentration Calculator
Recipe Scaler
Emoji Picker
Rainwater Collection Calculator
Scientific Calculator
Chemical Name Calculator
NOC Format
Fetal Weight Percentile Calculator
Battery Charge Time Calculator
ASCII to Morse Code Converter
Rent Calculator
Tax Bracket Calculator
Graduation Year Calculator
Irregular Polygon Area Calculator
Car Depreciation Calculator
Coffee Footprint Calculator
Mirror Clock Time