Free tool
Fuel Range & Trip Distance Estimator
How far the tank really goes, and whether the next servo is inside it.
True range (full + spare)
800km
Safe one-way leg (÷ 1.5)
533km
Tank-only range
533km
Fuel needed for this leg
68L
This leg fits.
Your 300 km hop is inside the 533 km safe leg. Recheck the number against current road reports before you count on the far pump.
Effective consumption after the terrain factor: 15 L/100 km. Enter your worst real average, not the brochure figure — and refuel at every confirmed servo rather than testing the reserve.
All calculations run on our servers from the values you enter — nothing is stored.
Please note — Results are planning estimates, not a substitute for current local knowledge. Fuel availability, road conditions and closures change without notice, so confirm supplies with the local shire, police road reports or the nearest roadhouse before relying on any stop. Never run a tank toward empty in remote country, carry a margin beyond this estimate, and always leave trip intentions with a contact.
Running out of fuel is the most avoidable emergency in remote Australia. It is also the one most often blamed on the map instead of the maths. This estimator checks the arithmetic before you commit: what you carry, what you burn, and how far that honestly gets you.
You enter tank size, real consumption, terrain, spare litres and the distance of the leg between the two fuel stops you plan to connect. The tool returns your true range, a safe one-way leg, and whether that leg fits inside it.
The core rule is not subtle. In remote country you carry fuel for one and a half times the distance you plan to drive. Headwinds, sand, loads and detours all spend the difference. When the maths says no, the answer is more cans or a shorter leg, never more optimism.
How the estimation works
It starts from consumption, not the brochure figure. A loaded 4WD with a roof rack, a fridge and a trailer drinks well above the sticker number. Enter your real average, or the honest worst guess, in litres per hundred kilometres.
Terrain then multiplies that figure. Sealed highway keeps it as it is. Mixed gravel and corrugations add fifteen percent. Soft sand, steep track and heavy crawling add thirty-five. The multiplier is deliberately blunt, because a fuel gauge is a worse storyteller than the road.
From there the tool computes true range: total litres carried, divided by adjusted consumption, times a hundred. That is the distance to empty, not the distance you should plan to drive.
The safe leg divides that range by one and a half. The gap between driving range and planning range pays for the detour to the lookout, the night you camp short of the roadhouse, and the wash-up that costs a day of idling.
A worked example
Take a loaded touring rig: an eighty-litre main tank, forty litres of spare, averaging fifteen litres per hundred on mixed roads. The terrain lift takes effective consumption to just over seventeen. The carried range comes out near seven hundred kilometres.
Divide that by one and a half and the safe one-way leg drops to around four hundred and sixty kilometres. A fuel gap of five hundred on the map does not fit. The answer is another twenty-litre can, or a rerouted stop, decided at home in calm light.
Run the same rig on sealed highway with no spare at all. The safe leg shrinks to about three hundred and fifty kilometres from one full tank. Long stretches look friendly on a map and thin on a gauge. The estimator shows which is true before the tank does.
Log two numbers as you drive: litres pumped and kilometres covered since the last fill. Division gives your true average on this terrain, which beats any factor this tool can guess. Refill the sheet every tank, and that sheet becomes the authority for the next leg, not the brochure.
How to use this estimator
Use the worst-case consumption you have actually seen, not the one you hope for. If you have never run the rig loaded the way this trip will load it, add a litre and a half per hundred to your last real average and start there.
Measure the leg from the last verified servo, and remember that verified means open. Roadhouses close, pumps run dry and closures rewrite the map overnight. Check current fuel availability with the local shire or the police road report before relying on any stop.
Then compare the safe leg against your planned day. If the maths is tight, the fix is upstream: carry more capacity, shorten the hop, or change the route. Nobody has ever added fuel by willing the gauge at the last tap.
Interpreting your result
Three numbers do the work. True range tells you where empty actually sits. The safe leg tells you the longest single hop you should sign up for. The verdict tells you whether this specific plan fits, in one word, before you are committed to it.
If the result flags a shortfall, it names the litres you are missing. That is the shopping list for cans or a tank upgrade, and the decision point for the routing. Twenty short is a reroute. Sixty short is a trip the vehicle is not yet fitted for.
Read the terrain factor as a warning about your own averages too. A driver who gets eleven on highway and twenty in sand is one number away from a tow-rope afternoon. When you are unsure what is under the tyres ahead, pick the higher band and carry the spare.
The empty-third habit
Many remote travellers refuel whenever the tank drops below two thirds, whatever the map says. On long-gap days, that habit is what keeps the one-and-a-half rule funded.
Accuracy, assumptions and limits
The model assumes an even burn and a fair engine. Tyre pressures, load, roof-rack drag, a dragging brake and driver temper all move consumption by ten percent or more. None of them appear here because only your trip log can supply them.
Spare cans count in the maths with a caveat. Forty loose litres on a tray is not the same as a plumbed sub-tank: cans slosh, vent and get left at the last campsite. Their real advantage is refilling at every confirmed servo, not the paper range they add.
The one-and-a-half rule is itself a floor. Many outback operators plan twice the distance on unsealed country, and any trip facing long closures, dry-season burns or no comms should lean that way. This tool shows the honest minimum, nothing finer.
Nothing here replaces local knowledge. Fuel availability, track condition and closures change faster than any model. Confirm with the shire, the road condition report and the last roadhouse that actually took your card. Then let the calculator do only what it can: the arithmetic.
The formula
Safe one-way leg = (tank + spare) ÷ (consumption × terrain factor) × 100 ÷ 1.5
- Terrain
- A multiplier on your average: 1 highway, 1.15 mixed gravel and corrugations, 1.35 sand and rough track.
- Tank+spare
- Every litre you actually carry, from full tank down to the last can.
- ÷ 1.5
- The remote rule: carry fuel for one and a half times the distance you intend to drive.
- Shortfall
- Litres you are missing if the planned leg exceeds the safe range. The shopping list for cans or a reroute.
Planning rules by situation
| Situation | Planning rule | Notes |
|---|---|---|
| Sealed highway, roadhouses every 200 km | Leg under 70% of true range | Comfort margin for traffic and unplanned detours |
| Gravel and corrugations, light load | Leg under 60% of range | Consumption climbs with speed on washboard |
| Soft sand or steep track, full load | Leg under 50% of range | Recovery and idle time burn fuel without distance |
| Known gap over 400 km | Carry fuel for twice the gap | Confirm the far pump is open before relying on it |
| Past mobile coverage | Safe leg plus a shelter-in-place day | Waiting out weather or a breakdown still burns fuel |
Key terms
- True range
- The distance your total carried fuel covers at adjusted consumption, from full to empty. A planning input, never a target.
- Safe leg
- The longest single distance between fuel stops the estimator recommends, after dividing true range by 1.5.
- Terrain factor
- The multiplier on average consumption for surface conditions: 1 highway, 1.15 mixed, 1.35 sand and rough.
- Verified supply
- A roadhouse or servo confirmed open and pumping on current local advice. Confirmed this week, not on last year's blog.
- Sub-tank
- An added fixed tank, usually behind or under the tray, selected from the cab with a changeover switch.
Pro tips
- Refill at every confirmed servo, not at empty. Top-ups are cheap and the queue at the far pump is not.
- Log the needle against the trip metre each tank. Your real average always beats the sticker figure.
- Fuel weighs about 0.8 kg per litre. A full can rack is a load decision as well as a range one.
- Lower tyre pressures for sand, then air back up for sealed runs. Under-inflated tyres on highway quietly eat the margin.
× Common mistakes
- Budgeting the map distance and forgetting the detours and wash-ups inside it.
- Trusting a roadhouse from an old blog post instead of a current closure report.
- Driving to empty to test the reserve, then pricing the tow accordingly.
Frequently asked questions
Why divide the range by 1.5 instead of just using it?+
Because true range ends at empty, and empty in remote country is where problems start. Fuel pickup can damage pumps, recovery options are distant, and there is no margin for a detour. The extra half pays for the unexpected day, and it is standard practice in outback touring guides.
Do jerry cans really count as full range?+
In the maths, yes, with fair caveats. Loose cans slosh, vent and get left behind more often than plumbed tanks. The estimator counts every litre you declare. The honest version is the litres you would bet the trip on at the last confirmed servo, so count those first.
What consumption should I enter for a loaded 4WD?+
The worst real figure you have seen since the rig was loaded this way. Touring setups with racks, fridges and water commonly run two to four litres per hundred above the sticker. If you do not know your average, add one and a half to the brochure figure as a starting guess.
Is the rule different on sealed highways?+
Yes. Around towns and regular roadhouses, planning legs under 70 percent of true range is sensible, and the rest is comfort margin. The one-and-a-half divisor matters most where the next pump is uncertain rather than merely distant. Highway risk is lower, not zero.
What if the far roadhouse turns out to be closed?+
Then your fuel need just jumped, because the real distance doubled. That is exactly the scenario the spare half exists for, and why verified supply means this week, not last season. When a stop is unconfirmed, plan as if it is shut and carry accordingly.
Does terrain really change consumption that much?+
Soft sand can double it over short sections, and slow four-wheel-drive crawling burns fuel while covering almost no distance. The factors here are planning averages, not dyno figures. A loaded rig at thirty kilometres an hour through sand will beat the eighteen per hundred you feared.
How we built this calculator
- Written by
- Track & Canopy Editorial Team — Gear & Power Desk
- How we calculate
- The one-and-a-half-times rule and the terrain multipliers follow published Australian remote-travel guidance and motoring-club touring advice. Effective range is plain arithmetic from carried litres and adjusted consumption, then audited against the worked example above.
- Sources & standards
- Last reviewed
- 15 October 2026
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Track & Canopy — Practical gear advice for Australian conditions. Estimates are planning aids, not engineering advice.