Methodology
How our tools and figures are built
Every number on this site has a source, a date and a limit. This page explains where the numbers come from, how the calculators work, and where the tools stop.
What kind of tools these are
- Most are rule based calculators. You enter your numbers, the tool applies a published rule (for example the IRAS stamp duty schedule or the MAS TDSR limit), and it shows the result. The calculators do not use machine learning.
- The HDB price check is the one that uses transaction records. It reads a price range from recent HDB resale sales. It is not a valuation by a licensed valuer and not a bank valuation.
- Every tool shows two dates at the top. The page updated date is when the page last changed. The data as of date is shown where a tool uses dated data.
Sources
| Source | What we use it for | Where it appears |
|---|---|---|
| IRAS | Buyer's Stamp Duty, Additional Buyer's Stamp Duty and Seller's Stamp Duty schedules; rental income rules | Stamp duty, restructuring and rental yield tools |
| MAS | TDSR and MSR limits; 3 month compounded SORA from MAS eServices | Affordability, loan repayment, TDSR scenarios, mortgage rates |
| HDB | Resale levy, grants, minimum occupation period and ethnic integration rules | HDB tools |
| data.gov.sg | HDB Resale Flat Prices dataset | HDB price check |
| SLA | Bala's Table, for lease decay approximations on leasehold homes | Leasehold tail discount tool |
| CPF | Ordinary Account refund and cash and CPF rules | Net proceeds, progression and upgrade tools |
| URA | Price and rental baseline for the yield heatmap | Rental yield heatmap (its page explains the baseline) |
| Banks | Mortgage package terms | Mortgage rates page (indicative, see below) |
How the HDB price check works
- It uses HDB resale transactions from data.gov.sg for the window shown on the tool (currently February to July 2026).
- Transactions are grouped by town, flat type and storey band.
- A group is used only when it has at least 5 transactions. Thinner groups are not shown, because a small sample is not reliable.
- The result is a range, not one number.
How the calculators work
- You enter your inputs. The tool applies the rule and shows a breakdown you can check by hand.
- Where a result depends on an assumption, such as a lock in period or an interest rate you type in, the assumption is shown next to the result.
The mortgage rates page
SORA is taken from the MAS series, and its data date is shown on the page. Bank packages are indicative and change often. Check each package with the bank before you rely on it. We are adding a confirmed date for the bank rate table, and until it appears, treat that table as a guide.
Limits
- Estimates are not valuations for lending. Banks use their own valuations.
- Transaction data lags. A recent sale may not appear yet.
- Rules change. We update each tool when an announcement is made, and the page updated date shows when that happened.
- These tools do not give legal, tax or financial advice, and they do not decide what you should buy, sell or borrow.
Where we stop
| If you need to know | Go to |
|---|---|
| Who owns a property and what is registered on its title | SLA INLIS (paid per search) |
| Official market statistics | URA and data.gov.sg (free) |
| Whether you qualify for a loan, and on what terms | Your bank |
| Stamp duty or tax for your own case | IRAS, or a qualified professional |
| What to do next for your situation | A conversation with Winfred Quek, CEA R073319H |
Corrections
Found an error? Send it through the contact page with the page address and the figure you think is wrong. We will check it, correct it if needed, and update the page date.