Local welding supply shops are usually your fastest option

The easiest place to fill a CO2 tank is a welding supply store in your area. These shops stock CO2 regularly because welders use it constantly. You walk in with your tank, they weigh it, fill it, and charge you by the pound — usually $0.50 to $1.50 per pound depending on your region and tank size. The whole process takes 10 to 20 minutes.

To find one near you, search "welding supply" or "industrial gas supplier" plus your city name. Call ahead to confirm they fill CO2 tanks and ask what they charge per pound. Some require you to own the tank already; others rent tanks if you don't have one. Bring a valid ID — most shops require it for any gas purchase.

If you don't have a local welding shop, call your city's fire department non-emergency line and ask where industrial gas suppliers operate in your area. They know which businesses handle compressed gases legally.

Key Takeaways

  • Welding supply stores fill CO2 tanks faster and cheaper than other options, usually in under 20 minutes.
  • You pay by the pound of CO2, not by the fill — expect $0.50 to $1.50 per pound depending on location and tank size.
  • Some welding shops require you to own the tank; others rent tanks if you show up empty-handed.
  • Bring a valid ID, because compressed gas sales require identification in most states.
  • If you can't find a welding shop, call your city fire department's non-emergency number for a referral to the nearest industrial gas supplier.

What to expect when you arrive at a welding supply shop

When you walk in with your tank, tell the staff you need a CO2 refill. They will ask whether you own the tank or need to rent one. If you own it, they will weigh it empty, fill it to capacity, and weigh it again to calculate how much CO2 went in. That weight difference is what you pay for.

The staff will also inspect your tank for damage, rust, or expired safety certifications. CO2 tanks have a date stamped on them showing when they were last inspected. If your tank is past its inspection date, the shop may refuse to fill it or charge extra to have it re-certified. Ask about this before you hand over your tank.

Payment is usually cash or card on the spot. Some shops offer a small discount if you bring your own tank instead of renting one from them.

Restaurant supply stores and beverage equipment shops

If you need CO2 for a soda maker, kegerator, or aquarium, restaurant supply stores and beverage equipment shops often fill tanks. These places cater to bars, restaurants, and home brewers who use CO2 regularly. The process is the same as a welding shop — they weigh, fill, and charge by the pound.

The advantage here is that many of these shops are in shopping centers or downtown areas, making them easier to reach than an industrial welding supply yard. The disadvantage is that they sometimes charge slightly more per pound because they serve a different customer base.

Search "beverage CO2 refill" or "soda maker refill" in your area. If you have a local homebrew shop, call them — they almost always know where to get CO2 filled and may fill tanks themselves.

Big box stores with propane refill stations

Some Home Depot and Lowe's locations have propane refill stations in their parking lots. A few of these also fill CO2 tanks, but it is not standard. Call your nearest location and ask specifically whether they fill CO2 — do not assume they do just because they handle propane.

If they do fill CO2, the process and pricing are the same as a welding shop. The main advantage is convenience if you are already shopping there. The main disadvantage is that availability varies widely by location, so you may waste a trip.

Online tank rental and delivery services

If you cannot reach a physical location or need regular refills, some companies rent CO2 tanks and deliver them to your home or business. You pay a monthly rental fee plus a charge for the CO2 itself. This is more expensive per fill than walking into a welding shop, but it saves time if you refill often.

Search "CO2 tank rental delivery" plus your city name. Most of these services operate in urban and suburban areas but not in rural regions. Read the rental agreement carefully — some charge a deposit, some charge restocking fees if you return a tank early, and some require a minimum contract length.

What to bring and what to know before you go

Bring your tank, a valid ID, and cash or a card. If your tank is rented from a different company, bring the rental agreement or paperwork showing who owns it — some shops will not fill a tank they did not rent out.

Know your tank size before you call. Common sizes are 5-pound, 10-pound, 20-pound, and 50-pound tanks. The shop needs to know this to tell you how much the fill will cost. If you do not know your tank size, look for a label stamped on the side or bottom of the tank.

Ask about their payment methods when you call. Some small welding shops take cash only. Ask whether they charge extra for expired inspection dates — this can add $10 to $30 to your bill if your tank has not been certified in the last five years.

Why CO2 tanks need inspection and what happens if yours is expired

CO2 tanks are pressure vessels, and they are legally required to be inspected every five years to make sure they are safe to fill and use. The inspection date is stamped on the tank itself. If your tank is past this date, a welding shop can still fill it, but many will charge an inspection or re-certification fee.

Some shops will refuse to fill an expired tank altogether and direct you to a certified inspection facility. This is rare but does happen. If you plan to use a tank regularly, check the inspection date before you need a refill — do not wait until you are empty and in a hurry.

If your tank is very old or heavily rusted, the shop may condemn it and refuse to fill it at all. In that case, you will need to buy a new tank. New CO2 tanks cost $50 to $150 depending on size, or you can rent one from the shop for $5 to $15 per month.

Frequently Asked Questions

How much does it cost to fill a CO2 tank?

You pay by the pound of CO2, usually $0.50 to $1.50 per pound. A 5-pound tank costs roughly $3 to $7 to fill; a 20-pound tank costs $10 to $30. Prices vary by location and supplier. Call ahead to ask the exact price per pound in your area.

Can I fill a CO2 tank at a regular gas station?

No. Gas stations do not stock CO2 or have the equipment to fill it. They handle gasoline, diesel, and sometimes propane, but not CO2. You must go to a welding supply shop, beverage equipment supplier, or industrial gas distributor.

What if I do not own my tank and need to rent one?

Most welding supply shops and beverage equipment stores rent tanks. You pay a monthly rental fee (usually $5 to $15) plus the cost of the CO2 itself. Ask about the deposit — some shops require $20 to $50 upfront, which you get back when you return the tank.

How long does a filled CO2 tank last?

This depends entirely on how much you use it. A 5-pound tank for a soda maker might last one to three months if you use it daily. A 20-pound tank for a kegerator might last two to six months. There is no set timeline — it depends on your usage.

What do I do if my tank is too old to fill?

If the shop condemns your tank, you can buy a new one (usually $50 to $150) or rent one from them for $5 to $15 per month. Renting makes sense if you only need CO2 occasionally; buying makes sense if you use it regularly.