New Zealanders are in favour of reducing the amount drivers can legally drink before getting behind the wheel, with 70 per cent supporting a limit of 50mg of alcohol per 100ml of blood, a survey has found.

The Government last year proposed lowering the legal blood-alcohol limit from 80mg to 50mg - a proposal backed by health experts, and included as one of 153 recommendations in last month's Law Commission report on reducing alcohol-related harms.

Results from a UMR Research survey, released today, found 70 per cent of respondents supported lowering the limit to 50mg.

Nine per cent of men and seven per cent of women overestimated the amount the average person could drink before exceeding the current limit, the survey found.

It also found the level of support for lowering the limit increased after respondents were told how much the average person could drink before exceeding the current 80mg limit.

Respondents were given the Ministry of Transport's estimate of how much the average person could drink before exceeding the current limit - six standard drinks in 90 minutes - after which 76 per cent said they were in favour of lowering the limit to 50mg.

If the limit was lowered, the results suggest many people would set their personal limit at two standard drinks or less.

The survey found 58 per cent of men thought more than two drinks would exceed a 50mg limit for the average man, while 47 per cent of women thought more than one drink would exceed a 50mg limit for the average woman.

The results come from an online survey of 1000 people and had a margin of error of plus or minus 3.1 per cent.

- NZPA