320 Gallon Propane Tank chart
Geometric capacity 320 gallons. Maximum fill 80% (~256 gal propane). Gauge reads % of water capacity.
| Depth | Gallons | Liters | % Full |
|---|---|---|---|
| 1″ | 3 | 12 | 1% |
| 2″ | 9 | 34 | 3% |
| 3″ | 16 | 61 | 5% |
| 4″ | 25 | 94 | 8% |
| 5″ | 34 | 130 | 11% |
| 6″ | 45 | 170 | 14% |
| 7″ | 56 | 212 | 18% |
| 8″ | 68 | 257 | 21% |
| 9″ | 80 | 303 | 25% |
| 10″ | 93 | 351 | 29% |
| 11″ | 106 | 401 | 33% |
| 12″ | 119 | 451 | 37% |
| 13″ | 133 | 502 | 41% |
| 14″ | 146 | 554 | 46% |
| 15″ | 160 | 606 | 50% |
| 16″ | 174 | 658 | 54% |
| 17″ | 187 | 709 | 59% |
| 18″ | 201 | 760 | 63% |
| 19″ | 214 | 811 | 67% |
| 20″ | 227 | 860 | 71% |
| 21″ | 240 | 908 | 75% |
| 22″ | 252 | 955 | 79% |
| 23″ | 264 | 999 | 82% |
| 24″ | 275 | 1,042 | 86% |
| 25″ | 286 | 1,081 | 89% |
| 26″ | 295 | 1,118 | 92% |
| 27″ | 304 | 1,150 | 95% |
| 28″ | 311 | 1,178 | 97% |
| 29″ | 317 | 1,199 | 99% |
| 30″ | 320 | 1,211 | 100% |
Reading the gauge (don't stick a propane tank)
Propane vessels are sealed pressure vessels — you never open or stick them. Read the float gauge on top: it shows percent of water capacity, and gallons of propane = gauge % × water capacity. The inch table below is the underlying geometry, useful for cross-checking a suspect gauge against a delivery ticket. Maximum legal fill is 80%, so a healthy gauge tops out around there after a delivery.
About this chart
Source geometry: Nominal 30 in dia ASME vessel (250-class diameter, longer shell); cylinder length solved to nameplate water capacity.. Values are computed with exact partial-fill formulas (see methodology) — a circular/obround segment for the shell, plus dished-head volume solved so total capacity equals nameplate water capacity.
Propane note: your float gauge reads percent of water capacity. Gallons of propane = gauge % × 320. Maximum legal fill is 80%.
FAQ
How many gallons are in my 320 gallon propane tank at half depth?
About 160 gallons. Use the stick reader above for any depth.
Where do I measure from?
From the inside bottom of the tank, straight up to the wet line on your stick. Keep the stick vertical.
Why does my manufacturer chart differ by a gallon or two?
Manufacturer charts account for that tank's exact head shape and fittings; this chart is exact for the stated geometry. Differences are typically 1–3%. Maximum fill 80% (~256 gal propane). Gauge reads % of water capacity.