Is your HVAC system the right size?
Upload your Ecobee thermostat data and find out in minutes. No sign-up required.
Why Use HVAC Right-Size?
Data-driven insights to help you save money and stay comfortable
100% Private
Your data never leaves your browser. No accounts, no uploads to servers.
Instant Results
Get your sizing analysis in seconds. No waiting for manual calculations.
Data-Driven
Uses real runtime data from your thermostat, not rules of thumb or square footage estimates.
How It Works
Four simple steps to find your ideal system size
Download Your Data
Export runtime data from your Ecobee thermostat as CSV files.
Upload & Parse
Drop your CSV files here. We parse them instantly in your browser.
Run Analysis
We calculate your actual heating/cooling load from runtime patterns.
Get Results
See if your system is oversized, undersized, or just right.
Air Filter Selection Guide
Choosing the right filter is just as important as sizing your system. Our comprehensive guide covers MERV ratings, filter types, airflow tradeoffs, and a step-by-step selection framework.
Read the GuideReady to find out?
Upload your thermostat data and get a personalized sizing recommendation in minutes.