100 lb Propane Tank dimensions & weight
About 47.5 in tall and 14.9 in across, 70 lb empty and 170 lb full — about 23.6 gallons of propane.
| Spec | Catalog 49500 (2022) | Catalog 49501 (2020) |
|---|---|---|
| Overall height | 47.5 in | 46.6 in |
| Diameter | 14.9 in | 15.1 in |
| Tare (empty) weight | 70 lb | 71 lb |
| Water capacity | 238 lb | 238 lb |
| LPG capacity | 23.8 gal | 22.9 gal |
| Specification | DOT 4BW240 | DOT 4BW240 |
Sources: Manchester Tank, DOT 5 lb. - 100 lb. Catalog 49500 (portable DOT LPG cylinders) (09/2022); Manchester Tank, Steel Tanks & Cylinders for LP Gas Systems, Portable Steel Tanks Catalog 49501 (2020).
Why the two documents differ
Manchester's 2022 and 2020 catalogs disagree by 0.9 in on height and 0.2 in on diameter for the same 238 lb water-capacity cylinder, and on LPG capacity: the 2020 catalog's 22.9 gal is 80 % of the cylinder's water volume, the 2022 catalog's 23.8 gal is not. Neither says why the dimensions changed.
Both agree on the water capacity, so both hold the same 100 lb of propane. For clearance, plan on the larger of each: 47.5 in tall and 15.1 in across.
Propane left by weight
Weigh the cylinder and subtract the TW stamped on its collar. The table uses the 2022 catalog's 70 lb tare and runs from empty to the full 170 lb.
| Scale reading | Propane left | Gallons | Full |
|---|---|---|---|
| 70 lb | 0 lb | 0.0 gal | 0 % |
| 80 lb | 10 lb | 2.4 gal | 10 % |
| 90 lb | 20 lb | 4.7 gal | 20 % |
| 100 lb | 30 lb | 7.1 gal | 30 % |
| 110 lb | 40 lb | 9.4 gal | 40 % |
| 120 lb | 50 lb | 11.8 gal | 50 % |
| 130 lb | 60 lb | 14.2 gal | 60 % |
| 140 lb | 70 lb | 16.5 gal | 70 % |
| 150 lb | 80 lb | 18.9 gal | 80 % |
| 160 lb | 90 lb | 21.2 gal | 90 % |
| 170 lb | 100 lb | 23.6 gal | 100 % |
Gallons at 4.24 lb per gallon (liquid propane at 60 °F, methodology).
Run time
100 lb of propane is about 2.2 million Btu. Find the Btu/h rating on the appliance's data plate and read the closest row.
| Burner rating | From full | From half |
|---|---|---|
| 30,000 Btu/h | 71.9 h | 35.9 h |
| 60,000 Btu/h | 35.9 h | 18.0 h |
| 100,000 Btu/h | 21.6 h | 10.8 h |
| 150,000 Btu/h | 14.4 h | 7.2 h |
Heat content: EIA, 91,452 Btu per gallon of propane.
Between the 100 lb and the next size up
| Size | Height | Diameter | Empty | Full |
|---|---|---|---|---|
| 60 lb | 43.1 in | 12.5 in | 46 lb | 106 lb |
| 100 lb | 47.5 in | 14.9 in | 70 lb | 170 lb |
| 200 lb | 41.9 in | 24 in | 152 lb | 352 lb |
| 420 lb | 53.8 in | 30 in | 278 lb | 698 lb |
The 200 lb is shorter than the 100 lb but much wider. The 420 lb, commonly sold as a 100 gallon tank, has its own page.
On the collar
This cylinder is built to DOT specification 4BW240 (49 CFR § 178.61), and its rated 100 lb is 42 % of its 238 lb water capacity under § 173.304a. The stamped test date decides whether it can be refilled (§ 180.209).
FAQ
How tall is a 100 lb propane tank?
47.5 in tall and 14.9 in in diameter in Manchester Tank's 2022 catalog. Its 2020 catalog lists the same cylinder as 46.6 in by 15.1 in.
How much does a full 100 lb propane tank weigh?
About 170 lb: 70 lb empty plus 100 lb of propane. The empty weight stamped on your collar (TW) is the one to use.
How many gallons are in a 100 lb propane tank?
About 23.6 gallons when full: 100 lb divided by 4.24 lb per gallon. Manchester lists 23.8 gal in its 2022 catalog and 22.9 gal in its 2020 catalog.
How long will a 100 lb propane tank last?
From full, 35.9 hours at a steady 60,000 Btu/h and 71.9 hours at 30,000 Btu/h.
Sources and standards
- DOT 5 lb. - 100 lb. Catalog 49500 (09/2022)Manchester Tank & Equipment Co.https://www.mantank.com/upl/downloads/content-blocks/portable-dot-lpg-cylinders-5lb-to-100lb.pdfThe manufacturer's published figures for each cylinder size: LPG capacity in gallons, water capacity in pounds, overall height, diameter, tare weight and DOT specification, and that its 5 to 40 lb cylinders have an overfilling prevention device (OPD). Checked 2026-10-22.
- Steel Tanks & Cylinders for LP Gas Systems, Portable Steel Tanks Catalog 49501 (2020)Manchester Tank & Equipment Co.https://mcwane.com/upl/downloads/library/tanks-cylinders-for-lpg-systems-100lb-to-420lb.pdfThe manufacturer's catalog for 100 lb to 420 lb DOT cylinders and the matching vertical ASME tanks (28.6, 57 and 118 gal). Its 100 lb figures differ slightly from the newer Catalog 49500 (2022). Checked 2026-10-22.
- 49 CFR § 173.304a — Additional requirements for shipment of liquefied compressed gases (filling densities)U.S. Department of Transportation (PHMSA), via the electronic Code of Federal Regulationshttps://www.ecfr.gov/current/title-49/subtitle-B/chapter-I/subchapter-C/part-173/subpart-G/section-173.304aParagraph (d)(1) sets the maximum filling density for liquefied petroleum gas by its specific gravity at 60 °F. For 0.504–0.510, the band propane falls in, it is 42 percent of the cylinder’s water capacity by weight — which is where the 20, 100 and 420 lb ratings come from.
- 49 CFR § 178.61 — Specification 4BW welded steel cylinders with electric-arc welded seamU.S. Department of Transportation (PHMSA), via the electronic Code of Federal Regulationshttps://www.ecfr.gov/current/title-49/subtitle-B/chapter-I/subchapter-C/part-178/subpart-C/section-178.61The construction specification behind the “DOT 4BW240” marking on Manchester Tank’s 40 lb and larger cylinders.
- 49 CFR § 180.209 — Requirements for requalification of specification cylindersU.S. Department of Transportation (PHMSA), via the electronic Code of Federal Regulationshttps://www.ecfr.gov/current/title-49/subtitle-B/chapter-I/subchapter-C/part-180/subpart-C/section-180.209Sets how often a DOT cylinder must be requalified before it can be refilled. The interval depends on the method used (hydrostatic test or visual inspection), and is counted from the test date stamped on the cylinder.
- Thermal Conversion Factors — Monthly Energy Review, Appendix A (source documentation)U.S. Energy Information Administrationhttps://www.eia.gov/totalenergy/data/monthly/pdf/mer_a_doc.pdfWhere the Btu-per-gallon figures come from and how they were derived. Distillate fuel oil is 5.770 million Btu/bbl at 15 ppm sulfur and under, 5.817 at 15–500 ppm and 5.825 above 500 ppm — 137,400, 138,500 and 138,700 Btu per gallon respectively. Propane is 3.841 million Btu/bbl, or 91,452 Btu per gallon, estimated by EIA from NIST Chemistry WebBook enthalpy-of-combustion data and liquid density at 60 °F.
- Methodology — the partial-fill formulas and liquid densities used on this sitetankvolumecalc.comhttps://tankvolumecalc.com/methodology/Every chart value here comes from a closed-form partial-fill formula, not interpolation: circular segments for cylinders, a piecewise obround model for 275/330 heating-oil tanks, and scaled spherical caps for dished heads. Densities and their bases are tabulated there.
The manufacturer sheets and 49 CFR sections above were retrieved and checked on 2026-10-22; the other linked sources on 2026-09-02.