Calculator
BTO ballot chance calculator
Your estimated chance of being invited to book a flat, from the application rate, your ballot chances and who else is applying.
Your estimate
17%
About 1 in 5.9
By ballot chances
Assumes everyone invited books a flat, the most cautious case. If 40% declined, as HDB has reported in one exercise: 28%.
How to use it
- Find the application rate for your project and flat type on the HDB Flat Portal. Use the rate for your category (for example first-timers) when HDB publishes one.
- Enter the number of ballot chances HDB shows for your application.
- Optionally set the mix of other applicants and the share of invited applicants who decline.
The model and its limits are explained in the methodology. For a worked example and historical data, read how to interpret BTO application rates.
Common questions
What is a BTO application rate?
The number of applicants divided by the number of flats, for one flat type in one project. HDB publishes it during the application window, often separately for first-timers.
How many ballot chances do I have?
First-timer applicants generally get two ballot chances, second-timers one, and First-Timer (Parents & Married Couples) applicants an extra chance. First-timer families who have been unsuccessful before may get additional chances. Use the number HDB shows for your application.
Why can I be invited even when the application rate is above 1?
HDB invites applicants in queue order until the flats are taken. Many invited applicants decline to book, so more people are invited than there are flats.
Is this an official HDB figure?
No. It is an independent estimate from a published model. It does not cover quotas or priority schemes; HDB's ballot result is the only definitive answer.