120 Gallon Propane Tank chart
Geometric capacity 120 gallons. Maximum fill is 80% of water capacity (~96 gal propane). Gauge reads % of capacity.
| Depth | Gallons | Liters | % Full |
|---|---|---|---|
| 1″ | 2 | 6 | 1% |
| 2″ | 5 | 17 | 4% |
| 3″ | 8 | 32 | 7% |
| 4″ | 13 | 48 | 11% |
| 5″ | 18 | 67 | 15% |
| 6″ | 23 | 87 | 19% |
| 7″ | 29 | 109 | 24% |
| 8″ | 35 | 131 | 29% |
| 9″ | 41 | 155 | 34% |
| 10″ | 47 | 178 | 39% |
| 11″ | 54 | 203 | 45% |
| 12″ | 60 | 227 | 50% |
| 13″ | 66 | 252 | 55% |
| 14″ | 73 | 276 | 61% |
| 15″ | 79 | 300 | 66% |
| 16″ | 85 | 323 | 71% |
| 17″ | 91 | 345 | 76% |
| 18″ | 97 | 367 | 81% |
| 19″ | 102 | 387 | 85% |
| 20″ | 107 | 406 | 89% |
| 21″ | 112 | 423 | 93% |
| 22″ | 115 | 437 | 96% |
| 23″ | 118 | 448 | 99% |
| 24″ | 120 | 454 | 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 24 in dia ASME vessel; cylinder length solved so geometric capacity = 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 % × 120. Maximum legal fill is 80%.
FAQ
How many gallons are in my 120 gallon propane tank at half depth?
About 60 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 is 80% of water capacity (~96 gal propane). Gauge reads % of capacity.