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CFM per Ton Calculator

Who it's for: HVAC installers, startup technicians, and estimators.

Use this CFM Per Ton Calculator to turn a system tonnage and airflow-per-ton target into a total airflow planning number.

Calculator Inputs

Next Steps

  • Use measured external static and blower data for final airflow verification.
  • Humidity goals and coil performance often influence final CFM-per-ton targets.
  • Cross-check branch velocities after setting total airflow.

Worked Example

Example: A 3-ton system at 400 CFM/ton gives a 1,200 CFM planning target. Use that number as a starting point before checking duct size, static pressure, and balancing conditions.

How This Calculator Works

The calculator multiplies system tons by the selected CFM-per-ton target. It does not decide the correct target; it turns your selected planning target into total airflow.

  • Multiplies entered system tons by the selected CFM-per-ton target.
  • Reports total airflow as a first-pass planning value.
  • Shows non-binding guidance text for interpretation.

Airflow Planning Reference

Item Value Use
350 CFM/ton Lower selected target Sometimes used where latent removal or system specifics drive lower airflow.
400 CFM/ton Common planning target A common starting point, not a universal rule.
450 CFM/ton Higher selected target May be used for different sensible/airflow goals.

Common Mistakes

  • Assuming one CFM-per-ton value fits every system.
  • Using nominal tons without checking actual equipment capacity.
  • Skipping duct/static pressure checks after calculating airflow.

FAQ

No. It is a common baseline, but final targets depend on equipment, climate, and humidity goals.

Projects with different latent/sensible priorities may use lower or higher targets during design.

No. This is a planning calculation; final airflow should be measured and verified in the field.

In this MVP, heating mode only changes helper text; math remains system tons x CFM-per-ton.

When to Call a Professional

Use a qualified HVAC professional when the CFM per Ton Calculator result affects final equipment selection, duct design, commissioning, or permit documentation.

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CFM Airflow Calculator

Calculate required airflow CFM from room dimensions and target ACH so HVAC teams can estimate ventilation and comfort airflow requirements quickly.

Conclusion

Use the CFM per Ton Calculator result to understand total cfm, selected cfm per ton, guidance note from system tons, target cfm per ton, heating mode note toggle. Keep the input assumptions with the result so another person can reproduce the same estimate.

About This Calculator

About this calculator: HVAC installers, startup technicians, and estimators.

Educational planning estimate. Verify final HVAC decisions against load calculations, manufacturer data, and field conditions.

Written by BuildCalcTools Team - CFM per Ton Calculator methodology and field-use notes.

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