Road Tax in Singapore: How It's Calculated, Why It Rises

COE gets the headlines, but road tax is the cost that actually shows up on a schedule, year after year, for as long as you own the car. It’s also unusual among car costs in one specific way: it deliberately gets more expensive as the car gets older.

Here’s how the calculation works, and why an eleven-year-old car costs more to tax than an identical nine-year-old one.

The Two Things That Set Your Road Tax

For a standard petrol car, road tax comes down to:

Engine capacity — how many cubic centimetres (cc) the engine displaces
Vehicle age — how many years since first registration

Engine capacity sets the base amount. Age applies a surcharge on top. Everything else — the car’s value, your COE price, the brand — is irrelevant to this particular bill.

Engine Capacity Comes in Bands

Road tax isn’t a flat rate per cc. It’s banded and progressive, in a way that will feel familiar if you’ve looked at ARF tiers: each band has its own formula, and larger engines are charged at a steeper rate.

The practical effect is that the tax rises faster than the engine size does. Doubling your engine capacity does considerably more than double your road tax. The jump between a 1.6-litre and a 2.0-litre car is far larger than the 400cc difference suggests, because the extra capacity is being charged in a higher band.

This is one of the quieter reasons the Cat A / Cat B split matters beyond the COE itself. A car that lands in Cat B on engine capacity is usually also sitting in a more expensive road tax band — you pay twice for the same decision.

There’s also a rebate factor applied to the calculated figure. Rates and rebates are adjusted periodically, so the safest way to get a current number is to run your own car’s capacity through our road tax calculator rather than rely on a figure quoted in an article.

The Age Surcharge

Here’s the part that catches owners out, particularly those who’ve just renewed a COE.

Once a car passes ten years old, road tax stops being flat and starts climbing. A surcharge is applied as a percentage on top of the base road tax, and it increases with each additional year, up to a cap.

The escalation looks roughly like this:

Vehicle age	Surcharge on base road tax
Up to 10 years	None
Over 10 years	+10%
Over 11 years	+20%
Over 12 years	+30%
Over 13 years	+40%
Over 14 years and beyond	+50% (capped)

So a car that’s been renewed and kept to fifteen years pays one and a half times the base road tax of the same model at nine years old. The surcharge then stays at that cap for the rest of the car’s life.

Confirm the current bands and percentages with the LTA — these are policy settings and do get revised.

A Worked Example

Suppose a car’s base road tax works out to $1,000 a year. Here’s what the owner actually pays as it ages:

Age	Base	Surcharge	Annual road tax
9 years	$1,000	—	$1,000
11 years	$1,000	+10%	$1,100
12 years	$1,000	+20%	$1,200
13 years	$1,000	+30%	$1,300
14 years	$1,000	+40%	$1,400
15+ years	$1,000	+50%	$1,500

Across a full ten-year renewal, that owner pays roughly $13,000 in road tax rather than the $10,000 they’d have paid at the pre-ten-year rate — about $3,000 extra, purely because of age.

That $3,000 belongs in your renewal maths. It rarely appears in the mental arithmetic people do when weighing up the PQP, but it’s as real as the renewal fee itself.

Hypothetical figures — put your own engine capacity and registration date into the road tax calculator for your actual numbers.

Why the Surcharge Exists

It isn’t arbitrary. Older vehicles generally emit more and are less efficient than newer ones, and the escalating surcharge is a deliberate nudge toward turnover — it makes keeping a very old car progressively less attractive.

Whether that nudge should change your decision is another matter. A well-maintained car that costs $1,500 a year to tax is still cheaper than replacing it, and the surcharge is small next to a COE. It’s a factor, not a verdict.

Paying It

Road tax is paid in advance, typically in six-month or twelve-month blocks. Before it can be renewed, two things must be in place:

Valid motor insurance covering the period
A passed vehicle inspection, where one is due

Inspections become more frequent as a car ages, which is another running cost that quietly increases over time.

Let road tax lapse and you’re driving an untaxed vehicle — which carries penalties and, because insurance and road tax are linked, can create complications with cover. It’s an easy thing to forget, since the reminder arrives once or twice a year and the due date rarely coincides with anything else. Our My Car tool tracks the date alongside your COE expiry.

Electric and Hybrid Cars

Electric cars have no engine capacity, so they’re taxed on power output (kW) instead, using their own set of bands, and there have been additional flat components applied to EVs to offset lost fuel duty. The age surcharge concept still applies.

If you’re weighing up an EV, the road tax treatment is worth checking specifically rather than assuming it mirrors petrol — see our guide to COE and electric cars.

The Bottom Line

Road tax is set by engine capacity in progressive bands, then increased by an age surcharge that starts after ten years and climbs to a cap of around +50%. It’s the one major car cost that’s designed to rise as the car ages.

If you’re deciding whether to renew a COE, add the age-surcharged road tax across the renewal term to your total. On a ten-year renewal it can add a few thousand dollars that most people never account for.

Work out your exact figure with the road tax calculator, and use the COE renewal calculator alongside it to see the full cost of keeping the car.

Our free app can remind you before your road tax, insurance and COE expiry dates fall due — three deadlines that are easy to lose track of, and expensive to miss.

This article is for general information only and is not financial or tax advice. Road tax rates, rebate factors and surcharge bands are set by the LTA and revised from time to time; confirm current figures with the LTA or OneMotoring.