Sources and checks
Figures checked Nov. 10, 2026
Every figure on Cord & Tank comes from a named source. Pages with figures list them at the bottom, with the exact words on the source page and how each one was checked.
| Figures held | 62 general figures and 36 wood types |
|---|---|
| From US government or university pages | 51 of the 62 general figures |
| From other named sources | 11, each labeled "Other source" where it's used |
| Held back | 1 general figure we couldn't confirm, and figures for 4 wood types whose sources were doubtful. No number is shown for them. |
| Re-opened and matched by a second check | 56 general figures as they stand now, and 34 of the 36 wood types' rows (Nov. 9, 2026); the others were corrected after that check |
| Looked up blind, without seeing our figure | 17 key figures (Nov. 10, 2026) |
| Calculator tests | 234, including 37 worked examples printed in published sources |
Which sources count
We use the US government's own pages first, such as the Energy Information Administration, the Department of Energy and state agencies, then state university extension services. Where none of them publishes a figure, we use a named supplier or maker and label it "Other source" on every page that uses it.
How we turn prices into heat
Each fuel's price is divided by the heat in one unit of it, then by your appliance's efficiency. The fuel comparer shows a worked example.
When sources disagree
We say so on the page and show the range. For heat values we use the most current figure from the strongest official source. For wood we use the lowest heat figure and the highest weight, so estimates lean toward more wood, not less. For propane run times we use the lowest official heat figure, so times err shorter.
Dates
Every figure carries its own checked date, in the list at the bottom of each page.
What we don't do
We don't publish fuel prices: they change by place and by week, so you type in your own. We don't say any set-up is right for your home. For that, ask a qualified heating professional or your fuel supplier.
Spotted a figure that looks wrong?
Send us the page and the figure at figures@cordandtank.com, and we'll check it against the source.