Pet Goldfish Tank Setup Cost Calculator

Work out the full cost of a goldfish tank before you buy anything. The fish is usually the cheapest part of the setup, so this calculator adds up the tank, the filter and every other item, then shows what the tank costs each month and across the first year.

1. Enter how many goldfish you plan to keep, from 1 to 10.
2. Pick the goldfish type. Fancy goldfish need 20 gallons for the first fish, and common or single-tail goldfish need 40 gallons.
3. Enter the price of each item. Use your own store prices, and enter 0 for anything you already own.
4. Enter the price of one goldfish, plus your monthly food, water treatment and electricity costs.
5. Press Calculate or press Enter. The first-year total appears first and large, with the minimum tank size, the setup cost and the monthly cost below.

The calculator uses two simple rules. The tank-size rule gives the minimum tank size, and plain addition gives the costs. Recommended minimum tank size in gallons equals the base size for the first goldfish plus 10 gallons for each extra goldfish. The base size is 20 gallons for a fancy goldfish and 40 gallons for a common or single-tail goldfish.

One-time setup cost equals tank price plus filter price plus light price plus substrate and decorations price plus other equipment price plus fish price each times the number of goldfish. Monthly running cost equals monthly food plus monthly water treatment plus monthly electricity. First-year total cost equals one-time setup cost plus 12 times the monthly running cost. Our budget calculator can help you fit the monthly cost into your household budget.

A first-time keeper plans a tank for 2 fancy goldfish. The tank costs $120, the filter $65, the light $35, substrate and decorations $40, other equipment $45, and each goldfish $8. Monthly food is $8, water treatment $5 and electricity $4.

1. Minimum tank size: 20 gallons for the first fancy goldfish plus 10 gallons for the second fish = 30 gallons.
2. Fish cost: 2 fish at $8 each = $16.
3. Equipment cost: $120 + $65 + $35 + $40 + $45 = $305.
4. One-time setup cost: $305 + $16 = $321.
5. Monthly running cost: $8 + $5 + $4 = $17.
6. First-year total: $321 + 12 x $17 = $321 + $204 = $525.

As a second check, take 1 fancy goldfish with a $80 tank, a $50 filter, a $25 light, $25 of substrate and decorations, $30 of other equipment and a $5 fish. The setup cost is $215, the monthly cost is $13 and the first-year total is $371. The same steps work for any number of fish, so try your own prices in the tool above.

The number of goldfish moves the total most, because each extra fish needs a bigger tank and a stronger filter. With the same style of setup, 1 fancy goldfish costs $215 to set up, $13 a month and $371 in the first year. With 2 fancy goldfish the figures are $321, $17 a month and $525 in the first year. With 4 fancy goldfish they rise to $450, $21 a month and $702 in the first year.

The tank and the filter are the two biggest one-time lines, so they deserve the most shopping around. A larger tank costs more up front but holds water quality steadier, which means fewer emergency water changes. The filter matters even more for goldfish than for most fish, because goldfish produce far more waste than their size suggests. Buy a filter rated for at least twice the tank volume, and treat the filter as the line not to cut. Our pet snake enclosure setup cost calculator uses the same itemised method for another pet habitat, so you can compare setup budgets across pets.

Fancy goldfish and common goldfish need different tank sizes. Fancy goldfish, such as orandas, fantails and black moors, are slow swimmers with compact bodies, so the rule is 20 gallons for the first fish plus 10 gallons for each extra fish. Common or single-tail goldfish, such as comets and shubunkins, grow to 10 to 14 inches and swim fast, so the rule is 40 gallons for the first fish plus 10 gallons for each extra fish.

Do not mix the two types in one tank. The fast single-tail fish outswim the fancy fish at feeding time, and the fancy fish go hungry. If you are unsure which type you want, price both in the calculator. Four fancy goldfish need a 50 gallon tank, while four common goldfish need a 70 gallon tank, and the bigger tank costs more to buy and to filter. Our pet bird cage setup cost calculator prices another pet home the same itemised way.

Cycle the tank before the fish arrive. A new tank needs 4 to 6 weeks for the bacteria that process fish waste to grow, and adding fish before that cycle finishes is the most common beginner mistake. Buy the test kit first and check that ammonia and nitrite read zero before you buy the fish.

Goldfish are cold-water fish and do well in water from 65 to 72 degrees Fahrenheit, so most homes need no heater at all. Only buy one if the room regularly falls below 60 degrees. Skip the bowl entirely, since no bowl meets the 20 gallon minimum for even one fancy goldfish. Price the full setup, run the numbers once more with the prices from the shop you will actually use, and only then buy the fish.