The Buyer's Stamp Duty Calculator, Explained

Stamp duty is the largest cheque most buyers write outside the property itself, and it's the one most people estimate wrong — either by applying a single percentage to the whole price, or by misreading how ABSD works for a couple of mixed nationality. The Buyer's Stamp Duty Calculator computes both taxes exactly: BSD on its marginal tiers, and ABSD by your precise buyer profile — including the joint-purchase rule that quietly raises the bill for a lot of couples.

BSD is marginal — like income tax, not a flat rate

The single most common error is multiplying the whole price by one rate. Buyer's Stamp Duty is tiered, and each slice of the price is taxed at its own rate — exactly like income tax brackets. For residential property the tiers are: 1% on the first $180,000, 2% on the next $180,000 (up to $360,000), 3% up to $1,000,000, 4% up to $1,500,000, 5% up to $3,000,000, and 6% above $3,000,000. So a $2m home isn't taxed at 5% flat; it's 1% + 2% + 3% + 4% on the slices up to $1.5m, then 5% on the slice from $1.5m to $2m. The calculator shows the per-tier breakdown so you see where each dollar of duty comes from.

One rule that catches buyers of an under-valued or over-valued unit: BSD (and ABSD) are assessed on the higher of the purchase price or the market value. If you negotiate $1.5m but IRAS values it at $1.6m, your duty is calculated on $1.6m.

ABSD turns entirely on who you are

Additional Buyer's Stamp Duty is where the profile matters. It's a flat percentage on top of BSD, set by nationality and how many residential properties you already own:

A citizen pays nothing on a first home but 20% on a second — which is the entire reason decoupling exists. A foreigner pays a flat 60% regardless of count, and a company or trust pays 65%. These rates have held since 27 April 2023, with no change announced in Budget 2026.

There's a relief worth knowing: under Singapore's free-trade agreements, nationals of the United States, and nationals and PRs of Iceland, Liechtenstein, Norway and Switzerland, are treated as Singapore Citizens for ABSD. The calculator applies this automatically when you select those profiles.

The joint-purchase rule most calculators get wrong

Here's the trap. When two or more people buy together, ABSD is charged at the highest rate that applies to any one of them — on the entire purchase price, not apportioned by share. So a Singapore-citizen first-timer buying with a foreigner spouse doesn't pay a blended rate; the whole property is hit at the foreigner's 60%. A citizen who already owns a home, buying jointly with a first-timer, drags the second-property rate onto the full price. Many quick calculators average the profiles and badly understate the bill. This one applies the highest-rate rule, which is how IRAS actually assesses it.

How to read it

Open the Buyer's Stamp Duty Calculator, enter the purchase price and market value, and set each buyer's nationality and number of properties owned. Read the BSD breakdown to see the marginal tiers, and the ABSD working to see the driving (highest) rate and the total. Remissions — the married-couple ABSD refund when you sell your first home within six months of buying the second, for instance — are surfaced as notes, never auto-deducted, because eligibility depends on conditions only you can confirm.

A clear-eyed number here changes decisions: it's the difference between "we can stretch to a second property" and realising the 20% ABSD is $360,000 you'd never get back unless you restructure first. Know it before you commit, not after.

Calculate your exact duty at tribesg.com/stamp-duty/buyers.

Sources: TRIBE Buyer's Stamp Duty Calculator; BSD tiers (effective 15 Feb 2023) and ABSD rates (effective 27 Apr 2023) per IRAS, unchanged as at June 2026. Informational only; not tax or financial advice.

Silas Tan is a District Director at Huttons Asia and co-founder of TRIBE. This article is for informational purposes and does not constitute financial or investment advice. CEA Registration R000303I.