Propane Refill vs Exchange: The Real Dollar Math (April 2026)
Refill is cheaper by $5-10 per tank AND delivers 33% more propane. Exchange tanks are short-filled to 15lb. Here's the full math.
Side-by-Side: Same 20lb Tank, Different Fill Method
| Metric | Refill Station | Exchange Network |
|---|---|---|
| Typical price paid | $15-20 | $20-25 |
| Propane received | 20lb (full 80% fill) | 15lb (short-fill) |
| Gallons of propane | 3.76 gal | 3.53 gal |
| Cost per pound of propane | $0.85/lb | $1.47/lb |
| Cost per gallon equivalent | ~$4.50/gal | ~$6.23/gal |
| Tank ownership required? | Yes - you bring your tank | No - you swap for their tank |
| Can buy tank at exchange? | No | Yes (you keep the exchanged tank) |
Why Is Exchange More Expensive?
Exchange networks inspect, recertify, and maintain their tank inventory. That $40-60 recertification cost is amortised into every exchange transaction as a per-tank overhead.
Exchange tanks are filled to 15lb by convention, not 20lb. This has been the industry standard for decades. The 15lb fill reduces transport and storage liability and enables consistent flat-fee pricing. Blue Rhino and AmeriGas both publish the 15lb fill weight in their specifications.
Exchange tanks are sold through grocery stores, gas stations, and big-box hardware retailers. Each middleman takes a margin. Refill stations that own their own equipment have a simpler cost structure.
Exchange cages are at 60,000+ locations including 24-hour gas stations. The extreme accessibility commands a price premium. It's a convenience tax of $5-10 per fill-up.
When Exchange Is Actually Worth It
Refill wins on cost every time. But there are three situations where exchange is the right call:
Exchange gives you a tank to keep. Once you have it, switch to refill. You only ever pay the exchange premium once.
DOT-expired tanks (over 12 years old) cannot be refilled. Exchanging into a newer tank sidesteps the $40-60 recertification cost - if the exchange is less than that.
Exchange cages at gas stations are accessible 24/7. If you run out of gas at 11pm on a Sunday, exchange is your only option.