Home Energy Audit Calculator

This home energy audit calculator estimates your annual energy use, cost, and carbon footprint from your floor area, climate, HVAC system, insulation, appliances, and lighting — or start from one of six presets and adjust from there. You get an audit grade benchmarked against typical homes of the same size, a category breakdown chart showing where your electricity actually goes across heating and cooling, appliances, lighting, and always-on baseline load, and a targeted recommendation for the single change most likely to reduce your bill.

Pick a preset to start fast, or enter your own home profile below. Formula: Annual kWh = HVAC + Appliances + Lighting & Plug + Baseline, from your selected profiles and floor area.

Quick-Start Home Profiles

Pick the closest match to auto-fill every field below, or skip this and enter your own values.

Small Efficient Apartment

700 ft², 1 person, mild climate, minimal HVAC, tight envelope, efficient appliances.

Suburban Family Home

1,800 ft², 3 people, mixed climate, gas heat + central AC, average envelope.

All-Electric Modern Home

2,200 ft², 4 people, hot/cold climate, modern heat pump, average envelope.

Older Home, High Use

2,000 ft², 3 people, severe climate, older AC/furnace, leaky envelope.

Large Cold-Climate Home

3,200 ft², 4 people, severe long-season climate, electric resistance heat.

Smart Home, High Baseline

1,500 ft², 2 people, efficient envelope and appliances, but a high always-on load.

Home Profile

Not sure what a field means? Tap the ⓘ next to its label.

Conditioned Floor Area ft²

Occupants — using energy daily

people

Climate, HVAC & Envelope

These scale your HVAC estimate — not a live weather or utility lookup.

Climate & HVAC Season

HVAC Energy Profile

Envelope & Windows

Appliances, Lighting & Baseline Load

General profiles, not an itemized appliance list — pick the closest match.

Appliance Load Profile

Lighting & Plug Profile

Always-On Baseline Load — watts

Local Energy Rate

From your last utility bill — used only to estimate cost, not energy use itself.

Energy Rate — $/kWh

$/kWh

Your Results

Annual Energy Use

—

kWh/year

Estimated Cost

—

per month

Energy Intensity

—

kWh/ft²/yr

Audit Grade

—

vs. comparable homes

Carbon Estimate

—

lbs CO₂/year

Peak Load (Illustrative)

—

Formula: —

What's Driving Your Usage:

Reduction target to reach Efficient: —

Peak Load is an illustrative estimate — not a code-compliant electrical demand-load calculation. Sizing a backup generator? See the Generator Sizing Calculator for a full load calculation.

Energy Use by Category

This chart shows how your estimated annual energy use splits across HVAC, appliances, lighting & plug load, and always-on baseline load.

Results are for reference and estimation only. Verify all values before relying on them for renovation or purchase decisions. See full disclaimer below.

How to Use the Home Energy Audit Calculator

Start From a Preset or Enter Your Home Profile

Pick the closest quick-start preset to auto-fill every field, or enter your own conditioned floor area and number of occupants directly.

Describe Your Climate, HVAC, and Envelope

Choose your climate and HVAC season, your primary heating and cooling system, and how well your home holds conditioned air.

Set Your Appliance, Lighting, and Baseline Load

Pick the closest match for your appliances and lighting, then enter your always-on baseline load in watts and your local energy rate.

Review Your Results

Click Calculate. Results appear immediately — estimated annual energy use, cost, audit grade, carbon footprint, and a chart breaking down where that energy goes. Use Print to capture results as they appear on screen.

Energy Audit Reference — Annual Intensity by Grade

Audit Grade	kWh / ft² / yr	Interpretation
Excellent	Under 2.5	Low electric intensity for a home this size.
Efficient	2.5 – 4.5	Better than most comparable homes.
Typical	4.5 – 7.0	A common range for mixed-fuel U.S. homes.
High Use	7.0 – 10.5	HVAC, appliances, or baseline load are likely driving this up.
Very High	Over 10.5	Worth checking electric heat, older HVAC, or high standby load.

Frequently Asked Questions

How accurate is this home energy audit calculator?

This calculator uses a category-profile model — your climate, HVAC, envelope, appliance, and lighting selections each map to a typical annual energy allowance, anchored to U.S. national averages (EIA). It's a fast estimate for comparison and planning, not a substitute for a professional energy audit using a blower door test, infrared camera, or your actual utility bill history.

What's a good kWh per square foot for a home?

Under about 2.5 kWh per square foot per year is Excellent, 2.5 to 4.5 is Efficient, and 4.5 to 7 is Typical for a mixed-fuel U.S. home — see the reference table above. Above 10.5 kWh per square foot per year usually points to electric resistance heat, an older HVAC system, or a high always-on baseline load.

How is the carbon emissions estimate calculated?

Your estimated annual kWh is multiplied by 0.8231 lbs of CO2 per kWh, the U.S. national average emissions factor from the EPA's eGRID database (eGRID with 2023 data, released January 2025). This is a national average, not your specific utility's actual generation mix — regionally, actual emissions per kWh can be significantly higher or lower depending on your local grid.

Why does floor area matter so much for HVAC estimates?

Heating and cooling load scales closely with the volume of conditioned space — a larger home has more surface area losing or gaining heat and more air to condition. That's why HVAC energy use in this calculator scales directly with your conditioned floor area, adjusted by your climate and envelope quality.

Is the Peak Load estimate the same as a load calculation for a generator or electrical panel?

No. Peak Load here is an illustrative estimate of your home's typical simultaneous draw, useful for a rough sense of scale. It is not a substitute for the NEC-compliant diversified demand-load calculation an electrician or the Generator Sizing Calculator performs when sizing a backup generator or service panel.