Trimester Calculator
See exactly which trimester you are in today, the dates the trimesters start and end, and when full term kicks in.
Scan to open on your phone
Point your phone camera at the code to open this tool.
See exactly which trimester you are in today, the dates the trimesters start and end, and when full term kicks in.
How to use Trimester Calculator
- Open the toolNo signup and nothing to install; it works as soon as the page loads.
- Set “Estimated due date”
- Read the resultChange any input and the result is recalculated immediately.
Nothing you enter leaves your device
All of the work happens inside your browser. Whatever you type is never packaged up and sent to a server, and no request this page makes carries it.
That makes it safe for contract amounts, personal details and internal documents you would rather not hand to a third party — close the tab and it is gone.
What this tool does not do
Trimester Calculator only does what a browser can do on its own — it talks to no backend service. So it keeps no history for you and syncs nothing across devices; if you need a record, copy or download the result.
It is also not a substitute for professional judgement. For legal, medical or tax decisions, treat the output as a starting point rather than a final answer.
Frequently Asked Questions
- What week is the start of each trimester?
- Common medical convention: first trimester weeks 1-13, second weeks 14-27, third weeks 28 until birth.