Steal An Egg Weight Calculator
Updated · game data from the wiki as of 30 September 2026 · changelog
Short answer: divide your pet's weight by its base weight and raise the result to the power 37/60 (about 0.617). That is the size multiplier on its income. Double the weight and income goes up about 1.53×; 8 times the weight gives about 3.6×. A Kitsune at 2,080 kg is 8× its base weight of 260 kg, so it earns ×3.61 its base income: $6.49B/s with no mutations.
How weight changes income
Every pet in Steal An Egg has a base income and a hidden base weight. The weight on your pet card decides how far above or below the base income it earns. The community wiki's calculator, and another fan calculator that uses the same maths in a different form, give this rule:
The important part is the middle line. The exponent 37/60 is less than 1, so income grows more slowly than weight. Ten times the weight is about 4.1 times the income, and 100 times the weight is about 17 times. Past 125 times the base weight there is a soft cap: the exponent drops to 2/5, so a pet 1,000 times its base weight earns about 45 times its base income instead of 71.
Below base weight the wiki calculator uses a steeper curve (power 5/3). This case is rare and nobody has confirmed it in game, so treat results for underweight pets as rough.
Worked examples
A heavy Kitsune
Kitsune: base income $1.8B/s, base weight 260 kg. Yours weighs 2,080 kg.
- Ratio = 2,080 ÷ 260 = 8.
- Size = 8^(37/60) = 2^1.85 = ×3.6050.
- Income = $1.8B × 3.6050 = $6.49B/s, or $23.36T per hour.
A Dog past the cap
Dog: base income $2/s, base weight 25 kg. A 25,000 kg Dog is 1,000× its base weight, past the 125× cap.
- Size = 1,000^(2/5) × 125^(13/60) = 15.849 × 2.847 = ×45.1160.
- Income = $2 × 45.116 = $90.23/s. Without the cap it would have been $2 × 1,000^(37/60) = about $142/s.
Working backwards: how heavy for $10B/s?
To make $10B/s from one plain Kitsune you need a size multiplier of 10B ÷ 1.8B = 5.556. Undoing the power: 5.556^(60/37) = 16.1, and 16.1 × 260 kg = 4,195 kg. With a Golden mutation (×2.5) the same target needs only 950 kg.
Common mistakes
- Treating income as proportional to weight. A pet twice as heavy does not earn twice as much. It earns about 1.53 times as much.
- Dropping decimals. Pet cards show weights like 312.5 kg. Type them exactly; on light pets a few kg is a big ratio.
- Trusting a placeholder base weight. The wiki lists the same base weight for several pets from one egg (for example 35 kg for every Monster Egg pet, 13,000 kg for Rift pets). Those are flagged in the calculator. If your pet index shows a different base weight, type it in the base weight box.
- Forgetting the cap. Past 125× base weight, extra weight still helps, but much less. Don't pay a lot for an extremely heavy pet expecting the same growth.
- Mixing up "weight" and "size". In this tool weight is the kg number; size is the multiplier the weight gives.
Questions
How does weight affect income in Steal An Egg?
Income is multiplied by (weight ÷ base weight) to the power 37/60, up to 125 times the base weight. After that the power drops to 2/5. So doubling a pet's weight raises its income about 1.53 times.
Where do I find my pet's weight?
It's on the pet card in game, in kg. Type it exactly, decimals included.
What is a pet's base weight?
The weight at which a pet earns exactly its listed base income. The game doesn't show it directly; our numbers come from the community wiki's calculator data, and some of them are placeholders, which the calculator flags.
Is the weight formula official?
No. It comes from the community wiki and matches another fan calculator, but the developers haven't published it. If you check it in game and it's off, please send a correction.
More Steal An Egg calculators
- Pen income calculatorYour whole pen: income, time to afford, fuse check, compare.
- Mutation calculatorGolden, Rainbow and the rest, with both stacking rules.
- Fuse calculatorHow heavy a fused pet must hatch to beat the three you give up.
- Treadmill calculatorTime to afford every treadmill and trail.
To add up every pet you own, use the Steal An Egg pen calculator.