A generator with nothing plugged in still burns 0.002 L/h just idling. Add one fridge (0.008 L/h per tile), a television (0.003 L/h) and six lamps (0.0002 L/h each), and pzwiki’s own worked example puts total draw at 0.0222 L/h — enough to run a 10-liter tank for about 450 in-game hours, or 18.7 days. Every number below comes from the same page and the same formula; nothing here is a community estimate.
The formula, and what it needs
pzwiki states the runtime calculation directly: fuel remaining (liters) ÷ power demand (L/h) = runtime, in in-game hours. Power demand isn’t one number — it’s the sum of a 0.002 L/h baseline plus whatever’s plugged in within the generator’s 20-tile radius, and the page is explicit that some devices scale by how many tiles they occupy (a popsicle freezer is 2 tiles and draws 0.016 L/h, double the base fridge rate).
| Device | Power usage (L/h) |
|---|---|
| Baseline (nothing plugged in) | 0.002 |
| Fridge or freezer | 0.008 |
| Fridge + freezer (combo unit) | 0.013 |
| Stove | 0.009 |
| Lights | 0.0002 |
| Television | 0.003 |
| Washer or dryer | 0.009 |
| Gas pump | 0.003 |
Right-clicking a running generator and choosing “Generator Info” shows the live total load, per the page — the table above is what feeds that number, not a replacement for checking it in-game.
Seven tanks, seven runtimes
Using pzwiki’s own formula and its own 10-liter tank example as the constant, here’s what a full tank buys for combinations built only from the consumption figures above. The six-load combo below is pzwiki’s own stated example; the rest are this page’s arithmetic on top of the same source numbers, not separately confirmed scenarios.
| Load on the generator | Total draw (L/h) | Runtime from 10 L | In-game days |
|---|---|---|---|
| Baseline only, nothing plugged in | 0.002 | 5,000 hours | ≈208.3 |
| Baseline + 1 gas pump | 0.005 | 2,000 hours | ≈83.3 |
| Baseline + 1 fridge (1 tile) | 0.010 | 1,000 hours | ≈41.7 |
| Baseline + 1 stove | 0.011 | ≈909 hours | ≈37.9 |
| Baseline + 1 washer or dryer | 0.011 | ≈909 hours | ≈37.9 |
| Baseline + 1 fridge+freezer combo unit | 0.015 | ≈667 hours | ≈27.8 |
| Baseline + popsicle fridge (2 tiles) + TV + 6 lamps (pzwiki’s own example) | 0.0222 | ≈450 hours | ≈18.7 |
The gap between the cheapest and most expensive rows here is roughly 11x on the same 10-liter tank — a single stove or washer/dryer alone costs you more than four times the baseline-only runtime, and stacking a fridge, entertainment and lighting on top of that (the bottom row) cuts a full tank down to under three weeks.
What else draws from the same tank math
- The tank fills from a gas can and can only be topped off while the generator is off — there’s no siphoning fuel back out once it’s in, so overfilling past what you’ll actually use before a fuel run is fuel you can’t recover.
- Range is fixed regardless of variant or load: every generator powers a cylinder 20 tiles wide on the x-y plane and reaching 3 floors above and 3 below it — a 41-tile-diameter, 7-floor-tall cylinder. Devices outside that radius draw nothing and get no power, no matter how much fuel is left.
- Noise range is not the same as power range, and it isn’t the same across variants either: Lectro-Max and Premium Technologies generators are audible to zombies from a base 20-tile radius, the Old variant from 25 tiles, and ValuTech from 23 tiles — all wider than a quiet base wants, and none of it shrinks by running a lighter load.
- Durability differs by variant too, in the same direction as noise doesn’t: Premium Technologies has the highest listed durability (36), then Lectro-Max (30), Old (25), and ValuTech (24) the lowest. Below 20% condition a generator can break outright; at 0% it can catch fire or, in rarer cases, explode and hit-kill anyone nearby. A dying generator is a separate risk from simply running out of gas.
- Repairing one costs 1 Electronics Scrap per attempt, repairing
4% + (0.5 x electrical skill level)%of its condition — a level-10 electrical character repairs 9% per scrap, a level-0 character 4%. - Connecting a generator to a building’s power requires electrical level 3, or level 2 with the Inventive trait, the electrician or engineer occupation, or having read the How to Use Generators magazine — a gate that exists independent of fuel math entirely.
Why this matters before the shutoff clock runs out
One 42.21 change sits next to these numbers: the changelog says fridges and freezers now warm gradually on the day the power goes out. It describes the power going out, not a generator running dry, and gives no rate, so this page does not use it to adjust any figure here. The fuel-consumption table itself is not mentioned in the 42.21 changelog.
Every fresh save starts on grid power, and the first-week order already covers the two sandbox-dated shutoff clocks that end that free ride. Once the power’s off, the numbers above are what decide whether a generator actually buys you a functioning base or just a loud, short-lived one — and where a generator physically is in the world to begin with is a separate problem this page does not cover.
What this page didn’t confirm
- Whether the consumption table itself has changed since 42.13.1. pzwiki stamps this page for that build specifically; the stable build at the time of that check was 42.20.4, six major point-releases before 42.21, and nothing on the page flags the consumption numbers as re-checked since.
- A generator’s actual maximum tank capacity in liters. The page states the tank holds “up to 1 gas can’s fuel,” but the only liter figure anywhere on the page is the 10-liter tank used in its own single worked example — not stated as the fixed maximum.
- Whether every device in the table scales per-tile the same way the fridge/freezer row does. The popsicle-freezer example (2 tiles x 0.008 L/h = 0.016 L/h) confirms per-tile scaling for that one case; the page doesn’t restate it for stoves, washers or the other rows.
Sources
- PZwiki, Generator — read in full, including raw wikitext, 22 September 2026. Range and noise-radius figures per variant, the per-device consumption table, the runtime formula and its 10-liter worked example, tank-fill mechanics, durability-by-variant table, repair formula, and connection requirements. Page states it was last updated for 42.13.1; the stable build when this was checked on 22 September 2026 was 42.20.4 (42.21 followed on 28 September).
- Steam news, Project Zomboid news hub — checked 22 September 2026. Confirms “42.20.4 STABLE & 42.19.2 UNSTABLE & 41.78.21 LEGACY Hotfixes Released,” dated 26 August 2026, as the most recent stable release.
