BTU Per Square Foot Chart 2026
BTU per square foot for cooling and heating by climate zone, plus the ton conversion. 1 ton = 12,000 BTU . Mixed climate ~18 BTU /sqft cooling; a 2,000 sq ft home needs about 3 tons.
How many BTU per square foot do you need? Complete chart by room type and climate zone, with ASHRAE formula and worked examples.
HVAC BTU Sizing Guide
A common baseline is 20 BTU per square foot for cooling, so a 1,000- square - foot space needs roughly 20,000 BTU (about 1.7 tons). Adjust up for hot climates, lots of windows, or high ceilings, and down for shaded, well-insulated homes.
BTU per square foot tables for heating and cooling by climate zone and insulation. Find your rate, then calculate equipment size in one step.
BTU Requirements in U.S. Climate Zones
We include rules of thumb for estimating the necessary BTUs per square foot for cooling or heating a building in each climate zone. We also include maximum cooling and mazimum heating requirements based on 30-year temperature averages provided by the U.S. government.
BTU per square foot chart The trade shorthand: 20 BTU /sq ft for cooling in a moderate climate, 25-60 BTU /sq ft for heating depending on climate zone. The chart is the shortcut; ACCA Manual J is the real method when load actually matters. By Workshop Calcs Editorial Team · Last reviewed 2026-05-12 against ACCA Manual J 8th ed. and IECC 2024 climate zones.
How Many BTU Per Square Foot for Heating & Cooling (2026 Guide)
Learn the exact BTU per square foot you need for both heating and cooling. Covers all 7 DOE climate zones, insulation levels, and building types with detailed charts and adjustment factors.
BTU chart by room size — cooling and heating This static reference table uses Zone 4 (NYC, DC, Seattle) and average insulation as the baseline — the most common US scenario. It gives both cooling and heating BTU for each room size band. For other climate zones, use the interactive lookup above or the BTU per square foot table. Unlike a calculator, a chart lets you scan a range quickly ...
Air Conditioner BTU Chart by Room Size, Ceiling Height & Climate Zone ...
2025 AC BTU chart by room size with ceiling height, climate, insulation, sun, and occupancy modifiers. Includes BTU per square foot , quick examples, and a printable PDF.
Read the recommended BTU and equipment class on the right What the calculator does The calculator multiplies a baseline of 22 BTU per square foot by the relevant adjustment factors (climate, ceiling, sun, insulation, space type), then adds fixed amounts for extra occupants and kitchen heat gain.