Home Energy Audit Calculator
Estimate your annual energy waste, see where money is escaping, and identify the highest-ROI fix. The donut below breaks your bill into waste categories so the biggest target is obvious.
DIY screening only. For air-leak hunts and hidden insulation gaps, schedule a professional blower-door audit through your utility. Many offer it free.
Estimate your annual energy waste
Enter your home details and average bill. The result and donut chart show where money is escaping; the side panel flags the highest-ROI fix.
$810 estimated annual waste
Based on a 1,500 sq ft home with 10 windows, average insulation, and a 10-year-old HVAC system.
How accurate is a DIY energy audit?
A DIY audit catches the obvious issues (drafts, old equipment, missing insulation) that account for the majority of energy waste. A professional audit uses blower-door tests and infrared cameras to find hidden air leaks and insulation gaps. Start with DIY for quick wins, then invest in a professional audit before major upgrades.
Tips for success
- Air-seal before you insulate. Caulk and weatherstrip around doors, windows, and outlets first. A $10 tube of caulk can save $100+ per year in a drafty home, the best ROI of any energy upgrade.
- Adjust the thermostat 2°F. Set it 2 degrees lower in winter and 2 higher in summer. Each degree saves roughly 3% on heating and cooling. That's 6% with no equipment cost.
- Replace HVAC filters every 1–3 months. A clogged filter forces the system to work harder and bumps energy use up to 15%. $5 filter, double-digit return.
- Switch to LEDs everywhere. They use 75% less energy than incandescent and last 25× longer. Even at $5 per bulb, payback is under a year on bulbs you actually use.
- Lower the water heater to 120°F. Most ship at 140°F, wasting energy on heat nobody needs. Insulate the hot-water pipes too; both are 20-minute jobs.
Common mistakes
- Replacing windows before air-sealing. 60–80% of "window loss" is actually air leakage at the frame, not heat conduction through glass. A $20 tube of caulk often beats a $20,000 window replacement.
- Adding insulation over a leaky attic. Insulation slows heat transfer, but air leaks bypass it. Seal attic penetrations (around can lights, chimneys, vent pipes) BEFORE adding insulation, not after.
- Ignoring the ductwork. Leaky ducts can lose 20–30% of heated/cooled air before it reaches the rooms. Mastic sealant on duct joints (NOT duct tape, which fails) is a high-ROI half-day fix.
- Replacing HVAC at peak summer/winter. Demand drives prices up 20–40% during heat waves and cold snaps. Plan replacement in spring or fall for best pricing and contractor availability.
- Skipping the utility audit. Many utilities offer free or discounted professional audits with blower-door testing and infrared imaging. Even if you've done DIY, it catches hidden gaps DIY can't see.
This calculator provides ballpark estimates based on national averages. For precise numbers, schedule a professional energy audit through your local utility. Many offer it free, and some states provide rebates for recommended upgrades.
FAQ
What are the most cost-effective energy upgrades?
Air sealing (caulk and weatherstripping) is almost always the best return on investment, often paying for itself in under a year. Attic insulation is next, followed by a programmable thermostat. Window replacement is expensive and has a long payback period, so save it for last unless windows are single-pane or damaged.
How much can better insulation save per year?
Upgrading from poor to good insulation in an average-sized home typically saves 15-25% on heating and cooling costs. For a home spending $2,400/year on energy, that's $360-$600 in annual savings. Attic insulation alone can cut heating bills by 10-15%.
When should I replace my HVAC system instead of repairing it?
Replace when the system is over 15 years old and needs a repair costing more than 50% of a new system, when it uses R-22 refrigerant (phased out), or when energy bills keep rising despite maintenance. A new high-efficiency system can cut heating and cooling costs by 20-40%.
Do energy audits qualify for tax credits or rebates?
Many utilities offer free or discounted energy audits. Federal tax credits under the Inflation Reduction Act cover up to 30% of the cost of qualifying improvements like insulation, heat pumps, and energy-efficient windows. Check dsireusa.org for state and local incentives in your area.