Nearly everyone has the typical 20-pound (5-gallon) barbecue grill propane tank. But, how do you ACCURATELY know how empty or full your propane tank really is?

How much does an EMPTY propane tank weigh?

Answer: The “TW” (Tare Weight) listed on the tank’s collar. I have 4 tanks of this size. Two of them read 18 pounds, the other two list 16.6 pounds. Your tank may vary. Read on for more detail.

How much does a FULL propane tank weigh?

Answer: The listed “TW” (Tare Weight) plus 17 pounds (4 gallons of propane). So, two of mine will weigh 35 pounds when full and the other two will weigh 33.6 when full. Your “TW” on your tank may be different from mine. Check the collar.

Propane Tank Weight | Calibrated Gauge

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 bbq-size propane tank:

propane tank scale for bbq grill


Weigh The Propane Tank

Alternatively you could weigh your own propane tank, or other size tanks (e.g. a 30 pound RV propane tank). There’s a little math involved, but not a big deal…

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

First, you might use this multipurpose luggage scale:

Luggage scale up to 110 pounds


 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 (5-gallon) size barbecue grill tank will hold 47.6 pounds of water.

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

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.

4 Gallons of Propane, Not 5

80% is now considered “FULL” due to safety reasons. Refill stations will only fill a 20 lb propane tank to 80% of it’s maximum, or 4 gallons instead of 5 gallons. Here’s more about it and why they do that: How many gallons of propane in a 20 lb tank

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 it’s “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 picture above for my 20 & 30 pound portable propane tanks (bbq and RV).

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 4.25 pounds per gallon.

 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 will fill it. A typical bbq tank will be stamped 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

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