Questions about PropaneDays
How the forecast works, where its numbers come from, and who it's made for. Still stuck? Write to us.
Common questions
Do I need a sensor?
No. You read the gauge on your tank (the % dial under the lid) and type it in. A weekly email reminds you to log a reading.
How does it know how fast I burn propane?
It counts heating degree days, how far each day's average temperature falls below 65°F, between your readings, and works out how many gallons your house uses per degree day. Propane suppliers schedule automatic deliveries the same way.
How accurate is it?
The first forecast uses a typical rate and is marked as an estimate. After two readings it uses your house's own rate and gets better with each one. It's still a forecast: always check your gauge before you order.
What if I also cook or heat water with propane?
Tell it what runs on propane. Those uses are counted as a daily base amount on top of heating.
Does it work for RVs and cabins?
Yes. Enter the tank size and the ZIP where the tank is. You can pause alerts when a cabin is closed up.
Will it order propane for me?
No. It tells you when to call your supplier, with your supplier's delivery lead time already counted in.
What does it cost?
The calculator is free. Daily forecasts and email alerts are $3 a month after 7 free days, with no card needed for the free days. Cancel any time from your account.
Why a fixed average fails in a cold snap
Most free calculators divide what's in the tank by a fixed number of gallons a day. That's right on an average day and wrong on the days that matter: on very cold days a propane furnace can use two to three times its average daily rate.
Degree days fix that. A day that averages 20°F counts 45 degree days; a 50°F day counts 15. A house burns roughly the same gallons per degree day all winter, so when the forecast turns cold, the burn goes up with it, and so does your reorder date.
How it learns your house
Your first forecast uses a typical rate for the kind of place you heat. Each time you log the gauge, PropaneDays takes the gallons used since the last reading (adding any fill you logged with its gallons), takes off the daily base for cooking, hot water and the rest, and divides by the degree days in between. With two readings it uses your house's own rate; from three intervals on it fits them all together.
Every morning at 5:00 (Eastern) it reads the new forecast, works your tank forward day by day, and checks the date you'll reach your reorder level against your supplier's lead time.
Where the weather comes from
ZIP lookup, daily mean temperatures for the past weeks and the next 16 days, and three years of history all come from Open-Meteo (data under CC BY 4.0). Past 16 days, the forecast uses the average degree days for the same calendar dates over the last three years.
Who it's for
Homeowners, cabin owners and RV households who heat or cook with propane and order deliveries themselves (will-call), from the Northeast and Midwest to the mountain states. On automatic delivery, your supplier already watches the tank for you.
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