Free HVAC & AC Calculators
Professional-grade tools to calculate BTU, tonnage, electricity costs, and more. Make informed decisions for your air conditioning needs.
Quick Room Calculator
Click a room size for instant results
10x10
100 sq ft
0.75 Ton12x12
144 sq ft
1.0 Ton15x15
225 sq ft
1.5 Ton20x15
300 sq ft
1.5 Ton20x20
400 sq ft
2.0 Ton25x25
625 sq ft
2.5 TonTrusted by HVAC Professionals Worldwide
ASHRAE Standard
Industry formulas
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Free HVAC Calculators
Industry-standard tools designed by HVAC professionals for accurate results you can trust.
Trusted by HVAC professionals worldwide
Our calculators use industry-standard formulas from ASHRAE and Manual J guidelines, ensuring you get accurate results every time.
Instant Results
Get real-time calculations as you type with no waiting
Industry Standard
Formulas based on ASHRAE and Manual J guidelines
PDF Export
Download and share your results as professional PDFs
Multi-Unit Support
Switch between metric and imperial units easily
100% Free
No hidden costs, subscriptions, or registration required
Smart Recommendations
Get actionable advice based on your specific needs
AC Running Costs by Country
Calculate electricity costs using local tariffs. Each country page uses actual local electricity rates.
Free AC Maintenance Checklist
Get our comprehensive PDF guide to keeping your AC running efficiently all year round. Save money on repairs and extend your unit's lifespan.
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