If you think a census question is outdated, or one's missing, you can have your say.

Statistics New Zealand is calling for public input on their website ahead of the next census in 2018.

Minister of Statistics Craig Foss says the census is in a constant state of flux, with questions changing more often than people realise.

"If we think back years and years ago, they've actually changed a lot. We used to ask how many washing machines people had, and things like that. That data's available in another forum now."

Foss says as society changes, the questions asked in the census need to reflect that.

"New and emerging things in 2018, such as technology, such as issues that are more relevant or have more interest to people at that time then perhaps they did in earlier census [need to be reflected]."