# Mutation chance calculator for Steal an Egg | STEAL EGG

Canonical: https://stealegg.com/en/guides/mutation-chance-calculator/

Language: en

[STEAL EGG](/en/)/[Related tools and records](/en/guides/)PLANNING TOOL

# Mutation chance calculator for Steal an Egg

Plan how many consumables to save. Enter a per-attempt chance and cost, then compare your chosen attempts with a target such as 90% or 95%.

STEAL EGG · 2026-10-19

A high chance does not guarantee success.

The model assumes independent attempts with the same chance each time and no progressive guarantee or pity. If the game uses other rules, this model does not account for them.

## Nitro examples: 10% and 475 trophies

 | Number of attempts | Chance of at least one success | Total cost

 | 22 | 90.15% | 10,450 trophies

 | 29 | 95.29% | 13,775 trophies

 | 44 | 99.03% | 20,900 trophies

## Spectral · 25% · 500 Souls

The Helper walkthrough reports 500 Souls per Spectral consumable, a 25% application chance and a ×2.75 income multiplier. Older images show 1,000 Souls. Check the current Soul Extractor price: buying a consumable does not guarantee that the mutation will apply.

 | Number of attempts | Chance of at least one success | Total cost

 | 9 | 92.49% | 4500 Souls

 | 11 | 95.78% | 5500 Souls

 | 17 | 99.25% | 8500 Souls

[Sources and Spectral unlock guide ↗](/en/updates/halloween-dimension-update-9-guide/#answer-spectral) · [Helper · Spectral ↗](https://discord.com/channels/1536773161868198028/1537936451386343555/1561067846954651760)

How the calculation works

For n attempts with chance p, the probability of at least one success is 1 − (1 − p)ⁿ. Cost is attempts × unit cost. The target plan finds the smallest whole number of attempts that reaches your requested probability. Here p is the percentage divided by 100.1 − (1 − p)ⁿ

## Related tools and records

Application chance and income multiplier are different. Nitro’s ×2.75 income multiplier is not a 275% application chance. Use the income calculator for earnings.

[Mutation table ↗](/en/guides/mutations-guide/) · [Pet income calculator ↗](/en/guides/income-calculator/) · [Nitro Race ↗](/en/updates/update-8-mounts-nitro-race/#nitro)

## Egg mutation income calculator

Enter the income per second shown on your egg in the Sell Shop and choose the consumable mutations you plan to apply.

[Calculate egg income with consumables →](/en/guides/egg-mutation-income-calculator/)

Alien Trade-In shows an exchange of 500 UFO Debris for one Alien Mutation crystal, with a 15% chance of successful application. Buying the crystal does not guarantee application. The 15% is neither an income multiplier nor a chance of entering a UFO.[Abducted / Alien Mutation →](/en/guides/mutations-guide/abducted/)