Replacing a placed fish
Costs nothing and gains income immediately. Compare the new catch’s displayed rate with your weakest placed fish and swap if it is higher. There is no payback period to calculate because there is no cost.
Pull a Lucky Fish Income Calculator
Enter the money-per-second rates your placed fish display and this works out your income, how long the next upgrade takes to afford, and whether a paid upgrade pays itself back.
Your numbers
Enter what the game shows you
Read the money-per-second labels on your placed fish and add them up. The k / m / b shorthand works, so you can type 50m for fifty million.
Optional: is a paid upgrade worth it?
Result
What your numbers mean
- Income per minute
- 15,000
- Income per hour
- 900,000
- Still to save
- 50,000,000
- Time to afford it
- 2.3 days
Paid upgrade payback
Fill in the optional upgrade fields to compare a paid upgrade against a free replacement.
This assumes the same online earning rate for the whole period and no other spending. Offline earning has no published cap, so it is not included. Use the final displayed rate on each fish so mutations are not counted twice.
The two decisions this settles
Free replacement versus paid upgrade
Almost every early spending question is one of these two. They use the same arithmetic in opposite directions.
Levelling a fish you own
Has to earn its cost back. Divide the cost by the added income per second. A 12,000 cost for a 40/s gain pays back in 300 seconds. If that is longer than the upgrade will be useful, skip it.
Worked example
A real calculation, step by step
Suppose two placed fish display 100/s and 150/s. Your combined rate is 250/s, which is 15,000 per minute. A rod with 30,000 left to pay therefore takes 120 seconds — two minutes — assuming you change nothing else. The calculator above does exactly this with your own numbers, including the k/m/b shorthand so you can enter “50m” instead of writing out eight digits.
One caution the arithmetic cannot cover: money you intend to spend elsewhere. If you plan to buy training or a fish upgrade first, add those costs to the savings target or the estimate will be short. The full walkthrough with more examples is on the money guide.
Common questions
Income questions
How do I work out my income per second?
Add up the money-per-second label on every fish placed on your island. The total is your combined rate. The calculator on this page multiplies it into a per-minute and per-hour figure for you.
How long will it take to afford a rod?
Subtract the money you already have from the price, then divide by your income per second. If a rod costs 50 million and you hold 20 million at 100,000 per second, the remaining 30 million takes 300 seconds, or five minutes.
Should I replace a fish or pay to level it up?
A free replacement gives an immediate income gain. A paid level-up has to earn its cost back, so divide the upgrade cost by the added income per second to see the payback time. If that payback is longer than you will keep playing that save, the free replacement is better value.
Does this include offline earnings?
No. The arithmetic assumes your online earning rate continues for the whole period. No source publishes an offline earning cap or payout rate for this game, so including one would be a guess.
Why does a mutation label not simply multiply my income?
Because the income number already shown on the fish has had its modifiers applied. If a fish displays 400 per second with a 4x mutation, multiplying by four again counts the same bonus twice. Use the displayed number.