There's a new approach to tackle New Zealand's stubborn gender pay gap.  

Acting Minister for Women Louise Upston's announced a new tool businesses can voluntarily use to calculate the divide. 

It replaces plans from the previous Government to make reporting mandatory.  

The national pay gap is 8.6% and has typically sat around 9-10% for the past decade.   

Business leader Dame Theresa Gattung told Mike Hosking that unconscious bias plays a significant role in why it exists.  

She says a good chunk of the pay gap is unexplained, and doesn't just relate to women taking time out of the workforce to have children, for example. 

LISTEN ABOVE 

• Voluntary reporting is "starting to shift the dial" of the gender pay gap