BTU SizerSizing projects
One room is a calculation. A house is a project — every room in one sheet, quotes side by side, and the maintenance that keeps the size you paid for.
Equipment Replacement Tracker
Every piece of equipment with its install date and expected life, so the replacement is a planned purchase rather than an emergency call-out.
Filter and Service Schedule
Set the interval once and get the next twelve filter changes and service dates, with an email before each one.
HVAC Quote Comparison
Equipment, installation, extras and the ten-year running cost of each quote in one table — the total that decides, not the number on the front page.
Room Air Quality Plan
Purifier CADR for every room in one sheet, totalled — so a whole-house air plan is one table rather than six separate calculations.
Seasonal Changeover Plan
Two dates a year, set once — the spring and autumn changeover, with the checklist for each and an email before it arrives.
Whole-Home Cooling Sheet
Every room in one table — area, ceiling and rate per room — adding up to the cooling load for the whole floor plan, saved and shareable.
Free to use, Pro to keep
Every tool on this page works straight away, with no account and no limit on how often you use it. Put your numbers in and you get the answer, the same as on the rest of the site.
What Pro adds is memory and reach. It saves a setup to your account so it is there on your phone as well as the machine you built it on. It turns a result into a page you can send to somebody. It emails you when a date you set is coming, instead of leaving that to your own memory. And it takes the ads off — here and on every other site we run, on one subscription.
These tools exist because the ordinary calculators on this site answer a single question, and some questions are not single. A number you need again next month is not a calculation, it is a record.
See what is included on the Free and Pro page.