Comparison

Probability Sim vs Gacha Calc

Price, ratings, monetisation and update history for both apps, side by side β€” with what reviewers say about each.

Head to head
About

Probability Sim

Features
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Probability Simulator 1T Trials is a powerful simulation app that lets you test probabilities to the extreme. Run up to 1 trillion trials and calculate probabilities as low as 1 in a trillion. Choose from decimal, percentage, or fraction notation. Simultaneously run multiple probability events for complex calculations. Perfect for statistics enthusiasts, mathematicians, and anyone interested in random trials. Sharpen your probability intuition and gain real insights from large-scale simulations.

About

Gacha Calc

Features
Read full description

Are you a fan of in-game gacha draws, opening your wallet based solely on the hope of "This time, it has to drop"? The [Gacha Calc: Probability Sim] is your essential tool, helping you predict spending and make smarter drawing plans based on mathematical probability, not just intuition. Key Features - Accurate Probability Calculation (Independent Trials): Simply enter the item's drop rate (%) and your desired number of attempts. The app instantly calculates the "Probability of acquiring at least one item." - Predictive Table: We provide an easy-to-read table showing the minimum number of attempts and the estimated cost required to reach your target probability milestones (e.g., 50%, 90% success rate). - History Tracking: Conveniently save your calculation results and check your simulation data anytime in the history log, allowing you to track your past strategies. - Clean UI/UX: The app offers a simple, intuitive design that anyone can useβ€”no complex formulas, just instant input and immediate results. Stop Overspending Now! Instead of relying on vague expectations, use the [Gacha Calc: Probability Sim] to predict your goal achievement rate and optimize your spending.

Screenshots

Probability Sim2 screens
Gacha Calc4 screens

Verdict

The call

The clearest difference is in-app purchases: Gacha Calc at none against Probability Sim's 2. Gacha Calc also leads on update cadence (daily vs every 10 months). On price, ads, device support and iOS requirement there is nothing between them.

Scored on Price Β· Rating Β· Positive reviews Β· Number of ratings Β· Update frequency Β· Ads Β· In-app purchases Β· Monetization Β· Best chart rank Β· Devices Β· Requires iOS

CostPrice Β· In-app purchases Β· Ads Β· Monetization

Both are free to download. Probability Sim sells 2 in-app purchases, starting at $4.99 per month. Gacha Calc asks for nothing beyond the download.

UpkeepUpdate frequency

Probability Sim ships an update every 10 months, Gacha Calc daily. The most recent releases landed on October 22, 2026 and October 6, 2026 respectively.

Scorecard2 real differences Β· 4 level
Probability Sim versus Gacha Calc: the parameters behind the verdict, then further details
ParameterProbability SimGacha Calc
PriceFreeFree
Update frequencyEvery 10 monthsDaily β€” better
AdsYesYes
In-app purchasesYesNo β€” better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.014.0.0 β€” better
Further details β€” not scored
Size29 MB36 MB
Age rating4+17+
Developerkota tadahyeokjin cho

In-app purchases

2 purchases

Probability Sim

Subscriptions2
  • Ad-free for 1 month7 Days trial$4.991 Month
  • Ad-free for 1 year14 Days trial$49.991 Year
None

Gacha Calc

No in-app purchases

Questions

Is Probability Sim free?
Probability Sim is free to download, with in-app purchases available.
Is Gacha Calc free?
Gacha Calc is free to download, with no in-app purchases.
Do Probability Sim or Gacha Calc have ads?
Both Probability Sim and Gacha Calc show ads.
Which is updated more often, Probability Sim or Gacha Calc?
Probability Sim ships an update every 10 months, and Gacha Calc daily. Most recently, Probability Sim was updated on October 22, 2026 and Gacha Calc on October 6, 2026.

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