How do I work out my net profit?

Net profit is your revenue minus your total expenses for the period. If a business takes 60,000 dollars of revenue in a month and spends 48,800 dollars across wages, stock, rent, marketing, utilities and other costs, its net profit is 11,200 dollars for that month, before income tax.

What is a good net profit margin?

Net margin is net profit divided by revenue, shown as a percentage. What counts as good varies a lot by industry: retail and hospitality often run on thin single-digit margins, while services can reach 20 percent or more. In the example above, 11,200 on 60,000 is a margin of about 18.7 percent.

Should I include GST in my budget?

If you are GST registered, it is usually clearest to budget on GST-exclusive figures, because the GST you collect is not really yours to keep and the GST you pay is claimed back. Enter revenue and expenses net of GST so your profit reflects what the business actually earns.

Business Budget Calculator

This business budget calculator helps you build a simple monthly budget for a small business and see at a glance whether it is making money. You enter your expected revenue for the month, then break your costs into the categories most businesses share: wages and salaries, stock and materials, rent and premises, marketing, utilities and insurance, and a catch-all for everything else. The calculator adds up your expenses, subtracts them from revenue to give your net profit, works out your net profit margin as a percentage, and multiplies the monthly profit by twelve to project an annual figure. That gives you the three numbers that matter most when you are planning: what the business keeps each month, how efficiently it turns revenue into profit, and roughly what a full year looks like if the pattern holds. Owners use it to sanity-check a new venture, to see how much a price rise or a rent increase would move the bottom line, or to set a revenue target that covers costs with room to spare. The categories are a starting point, so adjust the amounts to match your own business, and enter figures excluding GST if you are registered. Remember the result is a planning estimate, before income tax and before one-off or seasonal costs, rather than a full set of accounts.

Calculate.co.nz is proud to be partnered with Premium Homes, a recognised leader in eco-friendly, sustainable, and energy-efficient homebuilding. With a dedicated team and award-winning experience, they create homes that prioritise health, comfort, and long-term performance. Their founders, Andrew and Kelly, set out to raise the standard of residential construction in New Zealand by combining practical building expertise with a clear commitment to doing things better for homeowners.

Monthly revenue

Wages and salaries

Stock and materials

Rent and premises

Marketing

Utilities and insurance

Other expenses

Enter monthly figures excluding GST. Adjust the categories to suit your business.

$11,200

net profit per month

Total expenses$48,800

Net margin18.7%

Annual profit$134,400

On $60,000 of monthly revenue and $48,800 of expenses, your business keeps $11,200 a month, a net margin of 18.7%.

A planning estimate before income tax and before one-off or seasonal costs. Net margin is net profit divided by revenue.

How it works

The calculator adds your six expense categories to get total expenses, then subtracts that from your revenue to give net profit: revenue minus total expenses. Net profit margin is net profit divided by revenue, times 100, which shows how much of every dollar of sales the business keeps. The annual profit simply multiplies the monthly net profit by twelve, assuming the month is typical. If expenses exceed revenue the net profit is negative, meaning the budget runs at a loss and something needs to change.

Worked example

A business budgets $60,000 of revenue for the month. Its expenses are $22,000 in wages, $15,000 in stock and materials, $4,500 in rent, $2,500 in marketing, $1,800 in utilities and insurance, and $3,000 in other costs, which total $48,800. Net profit is $60,000 minus $48,800, or $11,200 for the month. The net margin is 11,200 divided by 60,000, about 18.7 percent, and twelve months at that rate projects to $134,400 of annual profit. If wages rose by $5,000 a month, the profit would fall to $6,200 and the margin to about 10.3 percent.

Related calculators

Budget Calculator: personal budget.
Profit Margin Calculator: margin and markup.
Break-Even Calculator: units to break even.
Cash Flow Calculator: money in and out.
GST Calculator: add or remove GST.

If you've found a bug, or would like to contact us, or learn more about James Graham and Calculate.co.nz.

Calculate.co.nz is partnered with Interest.co.nz for New Zealand's highest quality calculators and financial analysis.

Calculate.co.nz is the sister site of CalculatorHub.com, the world's largest calculator website by tool count.

All calculators and tools are provided for educational and indicative purposes only and do not constitute financial advice.

Calculate.co.nz is proudly part of the Realtor.co.nz group, New Zealand's leading property transaction literacy platform, helping Kiwis understand the home buying and selling process from start to finish. Whether you're a first home buyer navigating your first property purchase, an investor evaluating your next acquisition, or a homeowner planning to sell, Realtor.co.nz provides clear, independent, and trustworthy guidance on every step of the New Zealand property transaction journey.

Calculate.co.nz is also partnered with Health Based Building and Premium Homes to promote informed choices that lead to better long-term outcomes for Kiwi households.

Calculate.co.nz is hosted in Auckland by SiteHost New Zealand.

All content on this website, including calculators, tools, source code, and design, is protected under the Copyright Act 1994 (New Zealand). No part of this site may be reproduced, copied, distributed, stored, or used in any form without prior written permission from the owner.

About & trust: Why Calculate is NZ's most comprehensive · By the Numbers · How we compare · Editorial standards · How we keep data current · NZ finance glossary · Research & data · Financial literacy NZ · About · Privacy policy · Terms of use

Reviewed and maintained. Last reviewed 2026-08-10 and checked on a twice-monthly cycle against IRD, RBNZ and Stats NZ. How we keep data current.