Steal An Egg Fuse Calculator
Updated · game data from the wiki as of 30 September 2026 · changelog
Short answer: fusing three of the same pet only raises your income if the one pet you get back hatches heavy enough to earn what all three earned together. Because income grows with weight to the power 37/60, that usually means about 6 times the weight of one of the pets you put in. Three Phoenixes at 2,500, 3,000 and 4,000 kg make $293.69M/s together, so the fused Phoenix has to hatch at 18,670 kg or more.
How the fuse break-even works
The Fuse Machine takes three copies of the same pet and gives you back one egg of that pet. It costs cash, the result is random, and the game does not publish the odds. Nobody has shown that the weight or mutations of the pets you put in carry over to the new one. So the useful question is not "what will I get?" but "what would I need to get for this to be worth it?" That number can be worked out exactly.
Each pet's income is its base income times a size multiplier from its weight, times its mutations. The size multiplier is:
Add up the three size multipliers. The fused pet needs a single size multiplier at least that big. Turning the size back into a weight means raising it to the power 60/37 (about 1.62) and multiplying by the base weight. Because 60/37 is bigger than 1, the weight you need grows faster than the income you are trying to replace. Three pets at exactly base weight have a combined size of 3, and 3^(60/37) is about 5.94, which is where the "about 6 times" rule comes from.
Worked example: three Phoenixes
A Phoenix has a base income of $85M/s and a wiki base weight of 2,500 kg. Say you own three, weighing 2,500 kg, 3,000 kg and 4,000 kg, with no mutations.
- Size multipliers: 2,500 kg is 1× base, so ×1.0000. 3,000 kg is 1.2×, so ×1.1190. 4,000 kg is 1.6×, so ×1.3362.
- Together they earn $293.69M/s (base income times the sum of the three multipliers).
- The fused Phoenix needs the same total size on its own. Converting that size back to a weight gives 18,670 kg. That is several times heavier than your heaviest Phoenix.
- If your pen is full, the fuse also frees two slots. Say you would fill each one with a pet that earns $40M/s. The fused Phoenix then only needs to hatch at 11,148 kg, because the two new pets cover part of the gap.
The freed-slot case is the one where fusing most often pays. If your pen is full of weak pets and you have spare stronger ones waiting, fusing three copies into one is a way to make room. The calculator above handles this with the "freed slot" box.
Secret Shrine fusions
The Secret Shrine in the Angels & Demons area combines two different pets into a third. At base weight and with no mutations, both known recipes lower your income, though each frees a pen slot:
| You give | Base income | You get | Base income |
|---|---|---|---|
| Pegasus + Skeleton Horse | $1.3B + $1.3B | Equinox | $1.8B |
| ArchAngel + World Burner | $5B + $5B | Aetheron | $6.9B |
Recipes from the wiki's Angels & Demons page and Game Rant (checked 2026-09-23). The Enchanted Forest update (3 October 2026) added a new secret fuse that isn't in our data yet.
Common mistakes
- Comparing the fused pet to one pet, not three. The new pet replaces all three. Matching your heaviest one is a big loss: with the Phoenix example it would cost you about two pets' worth of income.
- Assuming weight carries over. No source has shown that heavy input pets give a heavier result. Plan as if the result is random.
- Ignoring mutations. If your three pets are Golden and the new one hatches plain, it needs to be much heavier again. Pick the mutations your three pets have; the calculator assumes the fused pet keeps them, which is the best case.
- Forgetting the empty slots. If your pen has free space, the freed slots are worth nothing, so leave that box blank.
- Using a placeholder base weight. Some pets share one wiki base weight (for example every Monster Egg pet is listed at 35 kg). The break-even weight scales with base weight, so check it against your pet index.
Questions
How does the Fuse Machine work in Steal An Egg?
You put in three of the same pet and pay a cash fee, and you get back one egg of that pet. The outcome is random and the odds are not published. Sources: Game Rant (2026-09-23) and Steal An Egg Time's fusion guide (2026-09-13).
Is fusing worth it in Steal An Egg?
Only if the fused pet hatches heavy enough to out-earn the three you gave up, or if you need the pen slots. With three pets at base weight, the new pet must weigh about 5.94 times the base weight. Use the calculator above for your own pets.
Do mutations carry over when you fuse?
Nobody has shown that they do. The calculator assumes the new pet keeps the mutations of the three you used, which is the most generous case. If it hatches without them, it needs to be heavier still.
What does "freed slot income" mean?
Fusing turns three pets into one, which frees two pen slots. If your pen is full and you have other pets waiting, type what one of those pets earns per second. The calculator adds two of them to the fused side.
More Steal An Egg calculators
- Pen income calculatorYour whole pen: income, time to afford, fuse check, compare.
- Weight calculatorWhat your pet's kg does to its income, and the weight for a target.
- Mutation calculatorGolden, Rainbow and the rest, with both stacking rules.
- Treadmill calculatorTime to afford every treadmill and trail.
Want your whole pen's income instead? Use the Steal An Egg pen calculator, which also has a fuse check for pets you've already added.