Efficiency = gain ÷ cost
Divide how much an upgrade adds per second (or per tap) by its cost. The bigger number grows you more per unit spent.
| Upgrade | Cost | Gain per second | Efficiency |
|---|---|---|---|
| A | 1,000 | +10 | 0.010 |
| B | 20,000 | +250 | 0.0125 |
| C | 300,000 | +3,000 | 0.010 |
Here B is the most efficient. Costs rise by a fixed ratio per level (say 15%), so buying the same upgrade repeatedly lowers its efficiency until another one takes the lead.
Payback time
Payback time = cost ÷ added production per second. B above pays for itself in 20,000 ÷ 250 = 80 seconds. It is the same calculation flipped, but “profitable after 80 seconds” makes save-or-buy decisions easier. If payback is longer than the time left before your next prestige, skip it.
The milestone exception
In games where power doubles at certain levels, the upgrade just before a milestone suddenly becomes the most efficient. Going from Lv.24 to 25 adds one level and doubles the previous 24. If a milestone is three or four levels away, compute it as a bundle: (production after reaching the milestone − current production) ÷ total cost of the remaining levels.
Tap vs auto
| How you play | Prioritise |
|---|---|
| Open often and tap a lot | Tap power and keeping the combo up |
| Check in occasionally | Auto producers (they keep working while the app is closed) |
| First few minutes | Tap power to afford the first auto producer |
In the game
The BEST tag and milestone hint
The Boost tab in Infinite Universe lists three click power upgrades and five auto expansion devices, and tags the one with the highest “gain from one more level ÷ cost” in each section as BEST. Each device shows how far the next milestone is (Lv.25, 50, 100, 200, 400), for example “x2 power at Lv.50 (13 to go)”. The tag looks one level ahead, so when a milestone is a few levels away, use the bundle calculation above.
Buy amount and the half-price coupon
The Buy button at the top right cycles x1 → x10 → MAX. When you are just short of the BEST upgrade, a Half-price coupon (ad reward) may appear. Once you have auto devices, Overload 10 min x3 triples auto expansion for a while (followed by a 20-minute cooldown).
FAQ
Isn’t it better to buy the most expensive upgrade first?
Only if it is also the most efficient. At equal efficiency, buying the cheaper one first raises production sooner, which compounds.
Should I keep buying right before a Big Bang?
A Big Bang resets upgrade levels, so skip anything whose payback time is longer than the time left before you reset.
Infinite Universe: Idle Space Clicker
No sign-up, start playing right away, and every record stays on your device. Free on Android.