How Much Does a 20-lb Propane Tank Weigh? (Full, Empty & Tare Weight)

Nearly everyone has a typical 20-pound propane tank for their barbecue grill. But how do you know how empty or full your propane tank really is?

How Much Does a 20-lb Propane Tank Weigh?

• Empty (tare weight): ~17 pounds
  • (most empty 20-lb tanks fall between 16.5–18.5 lbs)
• A full 20-lb propane tank typically weighs about 37 pounds total.
  • (some refill stations add less, exchange stations are worse)
• Propane inside when “full”: 20 pounds
  • (20 pounds includes built-in 80% safety margin of tank)
• Gallons of propane when full: 4.8 gallons
  • (propane weighs ~4.2 lbs per gallon)

A standard 20-lb propane cylinder usually weighs about 16.5–18.5 pounds when empty (tare weight). Most commonly you’ll see tare weights around 17–18 pounds stamped on the collar or handle.

Pounds Remaining in Tank = (Measured Weight – Tare Weight)
Gallons Remaining in Tank = (Measured Weight – Tare Weight) / 4.2
Percentage of Full (%) = (Measured Weight – Tare Weight) / 20 × 100

Example using propane reference of 4.2 pounds per gallon:

• Total Measured Weight: 33 lbs
• Tare Weight (TW) on collar: 17 lbs
• Pounds of Propane in Tank: 33 – 17 = 16 lbs
• Gallons of Propane in Tank: 16 / 4.2 = 3.8 gallons
• Percentage of Full: (16 / 20) × 100 = 80%

How Much Does an EMPTY Propane Tank Weigh?

Most common real-world tare weight:
👉 About 17 pounds

Most empty 20-lb propane tanks weigh between 16.5 and 18.5 pounds, depending on the manufacturer. This is called the Tare Weight (TW) and is stamped on the tank collar.

An empty propane tank is the Tare Weight “TW” which is listed on the tank’s collar. I have four tanks of this size. Two of them are stamped TW 18 (older), the other two are stamped TW 16.6. Your tank may vary.

Typical Empty Weight of a 20-lb Propane Tank (Tare Weight)

Most standard BBQ-style 20 lb propane cylinders weigh about 17 pounds when empty. The exact weight varies slightly by manufacturer and valve hardware, but most fall within a fairly tight range.

Tank Type	Typical Empty Weight (TW)
Lightweight steel 20-lb tank	16.5 – 17.0 lbs
Standard steel 20-lb tank	17.0 – 18.0 lbs
Heavier steel / older tanks	18.0 – 18.5 lbs

How Much Does a FULL 20-lb Propane Tank Weigh?

A fully filled 20-lb propane tank typically weighs 37–38 pounds total. Again, for accuracy, factor in the tare weight of the tank. The tank’s safety margin is already built-in to the design.

Component	Weight
Empty tank (TW) printed on collar	16.5–18.5 lbs
4.8 Gallons Propane inside (full)	20 lbs
Total full weight range	36.5–38.5 lbs

If you’re wondering how much does a 30-lb propane tank weigh full? Just do the same math described above, except a 30-lb propane tank is considered “full” at 7.1 gallons or 30 pounds of propane. Empty tare weight of a 30-lb steel propane tank is typically ~25 lbs. I have these size tanks with my RV.

Do they ever really fill a 20-lb propane tank to capacity?

A properly filled 20-lb propane tank contains about 20 pounds of propane by weight. Refill stations that fill by weight typically come very close to this amount.

However, exchange tanks (like those at grocery or hardware stores) are often intentionally underfilled and may contain only 15–18 pounds of propane.

Bottom line:
Refill stations often get close to a true 20 pound fill, but exchange tanks frequently contain less. The only way to know for sure is to weigh the tank and subtract the tare weight (TW) stamped on the collar.

20-lb BBQ Tank Gauge for Propane Level

Here’s a quick and easy way to know how full your propane tank really is. Use a weight gauge that’s specifically calibrated for the typical 20-pound BBQ-size propane tank. We’re not necessarily looking for exactness here. Instead, we’re just looking for a reasonable approximation of how full or empty it is.

Hook, Lift, and Look:

➡ Check current price & reviews on Amazon

The following is a digital scale for propane tanks with capacities of 5 lb, 10 lb, 20 lb, 30 lb, or 40 lb. There’s a button at the top to select your tank size. This product might be convenient if you have more than just a typical 20-lb propane tank. Perhaps you also have a 30-pound RV tank (for example).

➡ Check current price & reviews on Amazon

Weigh the Propane Tank Yourself and Do the Math.

Alternatively, you can weigh your own propane tank using an ordinary hanging scale or by placing it on a floor scale. As explained above, there’s a little math involved, but it’s no big deal.

Hanging Weight – Tare Weight (“TW” printed on tank collar) = pounds of propane inside

(propane weighs ~4.2 pounds per gallon)

Here’s the most accurate way to find out how much propane is in your tank:

First, you might use this multipurpose luggage scale:

➡ Check price on Amazon

What are the The Stamped Numbers on the Collar of a Propane Cylinder?

All propane tanks have 2 weights stamped onto the top handle (the collar)

– One is the tank’s empty weight (“TW” – Tare Weight)

– The other is its full weight (“WC” – full with WATER… not propane… see below)

TW (Tare Weight)

This is the weight of the tank itself when empty.

WC (Water Capacity)

This is the weight of the water required to fill the tank (yes, water).

The typical 20-pound size barbecue grill tank will hold 47.6 pounds of water.

Regulations limit the propane level to not exceed 42% of the tank’s water capacity.

Long story short – Regulations require the maximum weight of propane in a typical barbecue grill tank to be no more than 42% of 47.6, or 20 pounds.

Subtract Tare Weight From Measured Weight

So, what do we do with this information regarding a propane tank’s ‘Tare’ weight?

How do you actually discover how empty or full your propane tank is?

Simply weigh your propane tank and subtract its “Tare Weight”

➡American Weigh Scale

You can use any scale. A floor scale, or a hanging scale. There are several hanging scales on the market. I’ve been using the one pictured above for my 20 & 30-lb portable propane tanks (for BBQ and RV use).

For example, I just weighed my BBQ grill tank and it weighs 32.6 pounds. The Tare Weight stamped on the collar is 16.6 pounds.

32.6 – 16.6 = 16 pounds of propane

20 pounds is considered maximum regulation full.
In my example, 16 pounds is 4/5 full, or 80%.

Propane weighs 4.2 pounds per gallon and does vary somewhat depending on temperature.

Need to convert that propane weight into gallons?
👉 Read: How Many Gallons of Propane Are in a 20-lb Tank (And How to Check Yours)

Tip! Depending on the weather conditions, you may actually see condensation on the sides of a propane tank. There will be a clear demarcation indicating the level of propane inside the tank!

Here’s a chart where you can check the stamped W.C. on your propane tank and cross-reference the maximum pounds of propane that it can hold. A typical BBQ tank will be stamped WC 47.6 or 47.8.

Propane Cylinder (Tank) Filling Chart

“WC” versus Maximum Pounds of Propane

2.39 — 1
4.78 — 2
7.17 — 3
9.56 — 4
11.9 — 5
14.3 — 6
16.7 — 7
19.1 — 8
21.5 — 9
23.9 — 10
26.2 — 11
28.6 — 12
31.0 — 13
33.4 — 14
35.8 — 15
38.2 — 16
40.6 — 17
43.0 — 18
45.4 — 19
47.8 — 20 (typical bbq grill size tank)
59.7 — 25
71.7 — 30 (my RV tank size)
78.8 — 33
83.6 — 35
95.6 — 40
105.1 — 44
119.5 — 50
239.0 — 100

Propane Tank Weight & Fill Level FAQs