EV vs Petrol Cost Calculator (Singapore, 2026)

Using the calculator step by step

Use this to compare total running cost of an EV vs petrol car based on your mileage, energy prices, and maintenance assumptions.

1. Enter monthly mileage.
2. Enter electricity vs petrol cost assumptions.
3. Compare monthly running cost difference; then consider depreciation separately.

Scenario library (sanity checks)

Use these simplified scenarios as sanity checks. Replace the numbers with your own situation.

• Example A (low mileage):

  800 km/month. If usage is low, fuel savings may be small; depreciation and upfront price matter more.

• Example B (high mileage):

  2,000 km/month. Higher mileage makes energy cost differences more meaningful. Test electricity tariff changes.

Methodology & assumptions

• Energy prices change; test ranges.
• Excludes depreciation differences; use a full ownership cost model for final decision.
• Planning model; not advice.

After you run the numbers, ask a second question: “If the cost difference is smaller than expected, which option still fits my lifestyle better?” This page is strongest when you combine the result with practical factors like charging convenience, route pattern, and whether you value simplicity over experimentation.

How to turn the result into a decision

• Annual mileage: the single biggest swing factor for the running-cost story.
• Home charging reality: if you cannot charge cheaply and conveniently, the EV case changes.
• Ownership period: the longer you hold, the more running-cost differences compound.
• Depreciation expectations: never assume the energy-cost advantage alone determines total value.

Inputs that deserve a second look

This is why break-even matters. A break-even is not just a neat number; it tells you how much usage you need before the efficiency advantage overcomes the rest of the cost stack. If you drive very little, a theoretical EV advantage may never show up in your actual ownership period.

The most common mistake is to compare only one cost line — usually charging versus petrol — and ignore the bigger ownership stack. The right way to use this page is to treat energy cost as one layer inside a broader ownership decision. If an EV saves on running cost but carries a much higher upfront or financing burden, the “cheaper per km” story can be true and yet incomplete. Likewise, if your mileage is low, the energy-cost advantage may take much longer to matter than people expect.

Where EV vs petrol comparisons usually go wrong

Before acting on the result, ask whether the output still makes sense after a conservative stress test. Good calculator use is not about precision to the last dollar; it is about avoiding decisions that only work in the optimistic case. If the answer still holds after you use harsher assumptions, that is usually a sign the decision is robust enough to move forward.

Output checklist

Re-run the calculator whenever one of the major assumptions changes meaningfully: rate, tenure, resale value, rent, energy cost, or your expected holding period. Small updates to these inputs often matter more than trying to make the original run more precise.

When to re-run the model

Use the model to see which assumptions matter most. Then spend your energy validating those assumptions rather than polishing less important inputs.

Even a good calculator cannot fully price convenience, stress, optionality, or the value of keeping your finances simple. That is why the best use of a tool like this is to narrow the range of sensible choices, not to pretend it can replace judgement. When the result is close, qualitative factors deserve more weight.

What the calculator cannot decide for you

Use the model to see which assumptions matter most. Then spend your energy validating those assumptions rather than polishing less important inputs.

Even a good calculator cannot fully price convenience, stress, optionality, or the value of keeping your finances simple. That is why the best use of a tool like this is to narrow the range of sensible choices, not to pretend it can replace judgement. When the result is close, qualitative factors deserve more weight.

What the model leaves out

• Reading one “base case” as a certainty.
• Forgetting fees, taxes, or frictional costs that sit outside the neat formula.
• Using unrealistic tenure or holding-period assumptions.
• Comparing options that are not truly substitutes.

Common interpretation mistakes

• Reading one “base case” as a certainty.
• Forgetting fees, taxes, or frictional costs that sit outside the neat formula.
• Using unrealistic tenure or holding-period assumptions.
• Comparing options that are not truly substitutes.

Mistakes to avoid when reading the output

Run one optimistic case, one conservative case, and one “messy real life” case. The messy case is the most useful: slightly worse rates, slightly lower resale, slightly higher costs, and a shorter holding period than planned. If the decision still looks acceptable, you have a more resilient answer.

Quick scenario ideas

These scenarios help separate genuine EV economics from headline enthusiasm.

• Driver with reliable charging access: an owner with home or regular workplace charging usually gets a cleaner EV case because charging cost and convenience are more predictable.
• High-mileage driver without convenient charging: EV ownership can still work, but time friction and charging access may narrow the apparent cost advantage.
• Low-mileage buyer tempted by the EV story: if you drive very little, the fuel savings may simply take too long to recover a higher purchase premium.

When the EV advantage usually holds up

The EV case is strongest when your pattern is boring in a good way. You drive regularly enough for lower running cost to matter. You have reliable access to charging at home or at work. You are not forced to rely on inconvenient public charging as your main routine. And you are willing to hold the car long enough for the purchase decision to be judged over several years instead of a short, speculative window.

That matters because EV economics in Singapore are rarely decided by one dramatic line item. They are decided by whether the ownership pattern is stable enough for smaller recurring advantages to compound. If charging is predictable, downtime is low, and your mileage is not trivial, the lower running-cost logic has room to work. If those conditions are weak, the spreadsheet may still show a paper advantage, but the lived experience may narrow or erase it.

A useful stress test is to ask: if charging becomes slightly less convenient, electricity slightly more expensive, and resale slightly softer than expected, does the EV still look acceptable? If yes, the decision is probably being carried by real economics rather than optimism. If no, the result was fragile to begin with.

What often makes petrol look cheaper than it really is

Petrol cars can feel easier to understand because the workflow is familiar. That familiarity often makes buyers under-model the recurring burden. People remember headline purchase price and maybe fuel, but fail to treat maintenance, wear-related repairs, and stop-start urban driving patterns as part of the ownership picture. A cheaper entry number is not the same as a cheaper multi-year decision.

This is why the model should be used alongside pages such as car maintenance and repair cost in Singapore and the car ownership cost calculator. The question is not whether petrol is simpler. The question is whether the simpler routine actually produces a better total outcome after usage, maintenance, and replacement risk are treated honestly.

References

• LTA

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