Excel formula for calculating NZ tax paid on annual income.

gistfile1.txt

=IF(B2<=14000,SUM(B2*10.5%),IF(B2<=48000,SUM(B2-14000)*17.5%+1470,IF(B2<=70000,SUM(B2-48000)*30%+7420,IF(B2>=70001,SUM(B2-70000)*33%+14020))))

Here's a slightly simpler version to prevent the problem mentioned by @LightspeedNZ:

=SUMPRODUCT((A1>{1;14000;48000;70000;180000})*(A1-{0;14000;48000;70000;180000}),{0.105;0.07;0.125;0.03;0.06})

Lambda limits you to one cell reference, which is a time saver:
=LAMBDA(x,SUMPRODUCT((x>{1;14000;48000;70000;180000})*(x-{0;14000;48000;70000;180000}),{0.105;0.07;0.125;0.03;0.06}))(A1)

Just to add that most PAYE calculators online are incorrectly using the formula for 1st April 2025 already. If you are calculating PAYE or total tax you may need to include the ACC Earners Levy of $2,276.53 pa.

Can the LAMDA formula be converted for monthly tax? @spmp @LightspeedNZ

Removed as thresholds are incorrect and will make result inaccurate.

I found the above formula for Google sheets wasn't correct. I've created custom functions for calculating FY25 and FY26 nz income tax in google sheets and published it on this gist: https://gist.github.com/benjamin-brady/e0b8f8737aa935e5b4d823369b7c0c31

Lambda function for FY25 blended rates:

=LAMBDA(x,SUMPRODUCT((x>{0,14000,15600,48000,53500,70000,78100,180000})*(x-{0,14000,15600,48000,53500,70000,78100,180000}),{0.105,0.0232,0.0468,0.0414,0.0836,0.0099,0.0201,0.06}))(A1)