CFM to Tons

Convert airflow to approximate tons of cooling using a common 400 CFM per ton rule of thumb.

Author

Prof. Yuki Nakamura

HVAC editorial contributor

Japanese-American sociologist at UC Berkeley, researching immigration policy impacts on second-generation identity

Reviewed by

Prof. Kenji Tanaka

HVAC content reviewer

Japanese materials scientist at Kyoto University, known for breakthroughs in sustainable polymer research

Last updatedFebruary 22, 2026

PublishedFebruary 22, 2026

Reference Values

Browse 20 reference values with individual detail pages for quick lookup.

Browse all reference values

CFM and Tons Converter

Convert between airflow and approximate cooling tons using a 400 CFM/ton reference.

Converted Capacity

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Reference Table

Use this complete table for quick lookup and internal linking to specific value pages.

CFM to Tons Reference
Airflow	Approx Tons	Nominal BTU/h
200 CFM	0.5 ton	6,000
400 CFM	1 ton	12,000
600 CFM	1.5 ton	18,000
800 CFM	2 ton	24,000
1,000 CFM	2.5 ton	30,000
1,200 CFM	3 ton	36,000
1,400 CFM	3.5 ton	42,000
1,600 CFM	4 ton	48,000
1,800 CFM	4.5 ton	54,000
2,000 CFM	5 ton	60,000
2,200 CFM	5.5 ton	66,000
2,400 CFM	6 ton	72,000
2,600 CFM	6.5 ton	78,000
2,800 CFM	7 ton	84,000
3,000 CFM	7.5 ton	90,000
3,200 CFM	8 ton	96,000
3,400 CFM	8.5 ton	102,000
3,600 CFM	9 ton	108,000
3,800 CFM	9.5 ton	114,000
4,000 CFM	10 ton	120,000

Frequently Asked Questions

Common questions about CFM to Tons, formulas, and typical use cases.

What does CFM to tons conversion assume?

This calculator uses a common comfort-cooling rule of thumb of roughly 400 CFM per ton.

Is 400 CFM per ton always correct?

No. Actual design CFM per ton can vary with humidity control goals, equipment, and operating conditions.

Can this convert in reverse from tons to CFM?

Yes. Multiply tons by 400 to estimate airflow under this rule.

Should I use this for final duct design?

Use it for quick sizing checks. Final design should use equipment data, static pressure, and full load calculations.

Methodology and Review

This page combines a live calculator, precomputed reference values, and FAQ content from the same conversion definition to reduce mismatch between calculator output and lookup tables.

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For compliance-sensitive work, verify final values against project requirements, governing standards, and manufacturer documentation.