What this calculator does
The What-If Calculator answers a simple question: if I bought these buildings, how much would it cost and how much base CpS would I gain? Enter how many of each building you own in the Current column, then raise the Sim column to the count you are considering. The table shows the CpS added per building and the total price of everything in between.
How building prices scale
Every building gets 15% more expensive each time you buy one. The price of your next building is base cost × 1.15^owned, rounded up. Buying ten at once costs the sum of ten of those prices, which adds up quickly: the tenth one costs about 3.5 times as much as the first.
This is why the calculator adds up each purchase individually rather than multiplying one price by the quantity. It is also why the cheapest-looking building is rarely the best buy late in a run, since you have already pushed its price far above its base.
Base CpS versus your real CpS
The numbers here use each building's base CpS, before upgrades, milk, prestige, synergies and buffs. That makes the tool good for comparing raw prices and the shape of the cost curve, but your real gain from a purchase will be larger.
For decisions based on your actual multipliers, paste your save into the Save Analyzer. It uses the Payback Period (also called PP), which is the number of seconds a purchase takes to pay for itself after counting your real CpS. Lower is better. The building database lists base costs and CpS for all 20 buildings.
Tips for using it
Try a few what-if scenarios side by side, for example ten more of your newest building versus fifty of an older one. The older building usually gives less CpS per cookie spent, because its price has already been multiplied many times. When two options are close, the newer building also counts toward achievements and unlocks its own tiered upgrades sooner.
Frequently asked questions
Why is my real CpS gain higher than the calculator shows?
This calculator uses base building CpS without upgrades, milk, prestige or buffs. The Save Analyzer uses your real multipliers.
Does selling buildings refund the full price?
No. Selling a building refunds a fraction of its current price, so buying and selling back loses cookies unless you have upgrades or auras that change the refund.