Pet age is gated by a single cumulative curve: floor(20 × age^2.02). The calculator subtracts cumulative XP at your current age from cumulative XP at the target (both ages clamped to 0–125), then divides by an effective XP rate. Baseline rate is 10 XP per second; the boost slider adds 0–200%, so effective rate is 10 × (1 + boost%/100). That is a planning model—your live rate can differ with activity, helpers, and patches—but the XP totals themselves follow the curve above.
What the curve looks like in numbers
- Age 25 → about 13,331 total XP
- Age 50 → about 54,069 total XP
- Age 75 → about 122,646 total XP
- Age 100 → about 219,295 total XP
- Age 125 → about 344,182 total XP (tool ceiling)
The jump from 25→50 needs roughly 40,700 XP (~1.1 hours at the 1× baseline). From 50→100 needs about 165,200 XP (~4.6 hours at 1×, ~3.1 hours at +50%, ~2.3 hours at +100%). Early ages look cheap; late ages dominate session length. Rarity does not change these totals—only your effective XP per second and which species deserve the grind.
Using the boost field without guessing
Set boost to 0 when you want the baseline clock. If you run XP auras, event bonuses, or heavier pets that clearly gain faster, measure one minute of real gain, divide by 600 (10 XP/sec × 60), and convert the ratio into a percent on the slider (1.5× rate ≈ +50%). Do not stack every possible buff you might own someday—overstated boosts make late ages look free and ruin session planning.
Session planning that respects the curve
- Choose a trade or ability milestone (often 25, 50, 75, or 100) instead of “max everything.”
- Enter current age and that target; note XP needed and estimated time at your measured boost.
- During short play blocks, push one pet across a cheap segment (for example 25→50). Save long 50→100 pushes for high-boost windows.
- After the timer, decide keep, trade, or stop: age raises ability scaling and list price, but hatch weight class still caps what buyers pay—pair this tool with the pet weight calculator and WFL trade calculator.
Species priority still matters for opportunity cost. Use the pet tier list and ability tools to pick which pets earn a 100 push versus a 50 flip. The XP math is identical; the return on hours is not.