FillWaterTanks game iconFillWaterTanks
Play on Roblox
Primary tool

Fill Water Tanks Calculator

Time one fill-and-sell loop and this calculator turns it into a pace plan: cycles per minute, cycles per hour, and water per hour at your current tank size. Around the tool you get the documented upgrade prices that change the inputs, a worked example from real game values, and the interpretation rules — all sourced and dated 2026-10-03.

Use the calculator
The tool

Cycle pace calculator

Player-entered timing only. The game shows your tank counter filling live — a phone stopwatch is accurate enough.

1 cycles/min · 60 cycles/hour · 6,000 water/hour

Method: cycles per minute = 60 ÷ seconds per cycle; water per hour = cycles per hour × water per cycle. Player-entered arithmetic only — no official game rate is assumed or implied.

How the math works

Fill Water Tanks pays per unit of water sold, so your income has exactly three levers: how long one cycle takes, how much water one cycle moves, and what each unit pays. The calculator measures the first two from your own numbers: cycles per minute = 60 ÷ seconds per cycle; cycles per hour = that × 60; water per hour = cycles per hour × water per cycle. Cash per hour is then water per hour × your effective payout multiplier — which the game computes from the Water Gain upgrade, your equipped pipe's money boost (x1.1 for the basic Rusty Pipe per the creator walkthroughs), and your rebirth boost. Keep water totals and cash totals separate: multipliers change cash, not cycle time.

Worked example (documented game values)

Say you just bought Water Tank level 3 — the documented $10 upgrade that raises capacity to 100 water (AllThings.how guide, updated August 27, 2026). You time one loop at 20 seconds of filling plus a 5-second sell drain, so 25 seconds per cycle. Enter 25 and 100: that is 2.4 cycles per minute, 144 cycles per hour, 14,400 water per hour. Before the upgrade, level 2's smaller tank took the same 25 seconds but moved less water per cycle — the calculator makes the capacity gain visible as a higher water-per-hour line. Add your first employee ($15, +10% fill speed) and the fill portion of the loop shortens; re-time the cycle and enter the new number to see the compound effect.

What changes each input

Cycle time falls with employees (+10% fill speed each, on a documented 20-employee ladder) and, from rebirth 3, with button workers who fill and sell for you. Water per cycle rises with tank levels and buttons (Copper +25% up to the final Underworld Button at +700%, per the Quacks walkthrough). Cash per sold unit rises with Water Gain, your best pipe, and rebirth/prestige boosts. The table below is the documented starter set — see the fill-and-sell guide for the full order and the tier list for the value-per-dollar framework on pipes and buttons.

UpgradeEffectPrice
Water Tank level 2Raises tank capacity above the 10-water level-1 cap$5
Water Tank level 3Raises capacity to 100 water per fill$10
Water GainSale multiplier starting at x1 — boosts the cash each sold unit of water pays$1 for the first step
Roll SpeedPipe-roll cooldown from 3s toward 2.8s (creators document a floor near 1.4s late-game)$15
Roll LuckPipe odds multiplier from x1.1 toward x1.2 per step (creators show stacked luck far beyond that)$35
Second pipe slotA second passive pipe on your plot$10M

Source: AllThings.how how-to guide (updated August 27, 2026); checked 2026-10-03.

Interpreting the result

  • Time at least three cycles and average them — the first loop after loading includes server lag and menu time.
  • Re-time after every employee, button, or tank purchase; reusing an old cycle time hides exactly the gain you just paid for.
  • Water per hour is a capacity plan, not a cash number — multiply by your in-game cash per sell to get the money line.
  • Overflow is wasted: if water sits at max while you idle, your real pace is the calculator's pace minus the idle time.
  • Rebirth resets cash upgrades but keeps tank levels, buttons, and pipes — re-measure rather than assuming the old pace survived.
FAQ

Calculator questions

The five questions players actually ask about measuring this game.

How does the Fill Water Tanks calculator work?

You time one complete fill-and-sell cycle — standing on the button until the tank maxes, stepping off, and letting the sell finish. The calculator divides 60 by your seconds per cycle to get cycles per minute, scales that to an hourly pace, and multiplies by the water your tank holds per cycle. It is pure arithmetic on your own observations.

Why doesn't the calculator prefill official fill rates?

Numbers Going Up has not published official capacity, fill-speed, or payout tables. Every game number this site carries is community-documented (fan guide, community wiki, credited creator videos, checked 2026-10-03), so the calculator starts from what you measure in your own session instead of a number we cannot verify.

What is a good cycle time in Fill Water Tanks?

Early on, expect a few seconds per cycle once upgrades land: each employee adds +10% fill speed (the community wiki documents a ladder to 20 employees), buttons raise water per fill from +25% up to +700%, and your tank level raises raw capacity. Time your own loop before and after an upgrade — the difference is the upgrade's real pace value.

What should I upgrade first for a faster cycle?

The documented starter prices make efficiency easy to see: Water Gain (x1 sale multiplier) for $1, Water Tank level 2 for $5, your first employee for $15, Roll Speed for $15, and Roll Luck for $35. Employees and buttons cut cycle time or raise water per fill; Water Gain raises what every sold unit pays.

Does the calculator account for pipes and rebirth boosts?

Indirectly. Pipes add money multipliers (x1.1 for the basic Rusty Pipe up to the crafted tiers) and rebirths add permanent boosts — both change cash per cycle, not the timing math. Enter your post-upgrade cycle time and tank size, and compare cash per cycle in game before and after the change.

Sources

AllThings.how — Fill Water Tanks how-to guide (updated Aug 27, 2026) — starter upgrade prices, loop, employees. Checked 2026-10-03.

Fill Water Tanks Wiki (Fandom) — 20-employee fill-speed ladder. Checked 2026-10-03.

Quacks — "I Made MILLIONS Selling Water" (YouTube, Aug 27, 2026) — buttons, pipes, rebirth behavior. Checked 2026-10-03.

Official Roblox game page — identity and official loop description. Checked 2026-10-03.