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New Zealand · 2024/25

Capital Growth Calculator

Calculate total and annualised capital growth on your property investment.

Last reviewed: 12 August 2025Source: HMRC / Welsh Revenue / Revenue Scotland
Capital Growth Calculator · NZProperty & Real Estate

Rates & sources

SDLT/LTT/LBTT bands vary between England, Wales, Scotland and Northern Ireland. Use the appropriate calculator.

Source: HMRC / Welsh Revenue / Revenue Scotland — figures refreshed at the start of each tax year.

When to use this calculator

  • Before buying, renting, refinancing, or reviewing a property investment.
  • When you want to compare cash flow, yield, growth, and ownership costs side by side.
  • When you need a fast estimate before speaking to an agent, lender, or adviser.
  • When you are assessing whether a rental property still makes financial sense after a mortgage rate change.
  • When you want to compare the total cost of renting against owning over a five- or ten-year horizon.

A realistic New Zealand planning example

Use these sample inputs as a quick scenario test, then change one variable at a time to compare outcomes.

Purchase Price (NZ$)

NZ$0.30

Current Value (NZ$)

NZ$1,400

Years Held

25 years

After entering these figures, review total growth, annualised and profit together rather than in isolation — each metric tells a different part of the story. Then rerun the tool with one input adjusted to see which variable has the biggest effect on all three outputs before you settle on a plan.

How to read your results

Total Growth

This is the headline outcome of the calculation, but it is most useful when read alongside the supporting metrics below it rather than in isolation. Try changing one input at a time and watching how this total moves to understand which driver has the biggest impact.

Annualised

Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.

Profit

Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.

Method & assumptionsAuthoritative sources

This calculator uses three inputs — purchase price, current value, and years held — to produce total percentage growth, annualised compound growth, and the absolute profit figure. Total growth is calculated as (current value minus purchase price) divided by purchase price, multiplied by 100. Annualised growth uses the compound annual growth rate formula: (current value divided by purchase price) raised to the power of one divided by years held, minus one, expressed as a percentage.

The profit figure shown is the gross gain before costs. A realistic net profit should deduct Stamp Duty Land Tax paid on purchase, conveyancing and survey fees, any capital improvements (which also reduce your CGT liability on disposal), and selling costs including estate agent fees and legal fees on sale. Capital Gains Tax is also payable on disposal of investment property; the chargeable gain should be reported to HMRC within 60 days of completion. The calculator does not account for inflation or rental income received during the holding period, both of which are relevant to an overall investment assessment.

Common mistakes

  • !Comparing rent and ownership costs without including taxes, fees, and maintenance.
  • !Using purchase price alone without testing the impact of financing or vacancy assumptions.
  • !Relying on yield or growth in isolation instead of reviewing the full property case.
  • !Forgetting Stamp Duty Land Tax (or its Scottish and Welsh equivalents), which can add thousands to the true cost of purchase.
  • !Using optimistic rental growth figures without also testing a flat or declining rent scenario to check downside resilience.

What to do next

  • Run a second scenario with a higher rate or lower rental yield to check downside resilience.
  • Compare the result with a buy-versus-rent or stamp duty calculator before making an offer.
  • Use the related guides below to understand agent fees, legal costs, and ongoing maintenance budgets.
  • If you are assessing a buy-to-let, check the gross yield against the net yield after mortgage interest, voids, and management fees.
  • Note down the key figures from this scenario to share with your solicitor or mortgage broker so they are working from the same assumptions.

Frequently asked

Nationwide and ONS data show UK average house prices have grown around 4-5% nominal per year over the last 30 years, or roughly 2-3% real (after inflation). Growth is very uneven by region: London outperformed 2000-2016 but has lagged since, while the North West and Scotland have led 2020-2024.

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