Useful next calculations
Rates and sources
Standard amortisation formulas used across UK lenders. Interest rates move daily — confirm with your lender or broker.
Source: Bank of England — Statistics. Check the linked guidance and any live quote before acting.
When to use this calculator
- Before comparing mortgage products, brokers or repayment types.
- When you want to test how a different deposit, rate or term changes the payment.
- When you need a quick estimate before using a formal illustration or agreement in principle.
- When you are stress-testing your budget against a higher rate.
A worked example
These are the example figures the calculator opens with.
| Input | Value |
|---|---|
| Property price (£) | £300,000 |
| Deposit you plan to pay (£) | £30,000 |
| Legal and conveyancing fees (£) | £2,000 |
| Survey and valuation costs (£) | £800 |
For those figures the calculator returns:
- Cash needed before property tax: £33,800.00
- Costs entered: £3,800.00
- Savings gap: £8,800.00
- Savings left: £0.00
- Deposit: 10.00% of Price
How to read your results
Cash Needed Before Property Tax
Review this figure alongside your gross income so you can understand deductions before the tax year closes. It is a planning estimate, not a filed return.
Method & assumptions
This UK-only planning tool adds only the cash figures you enter: deposit, legal and conveyancing fees, survey or valuation costs, moving costs and other upfront costs. It deliberately excludes Stamp Duty Land Tax because the outcome depends on the property, location and buyer circumstances. Use the linked SDLT calculator for England and Northern Ireland, then verify the amount with your conveyancer.
It does not decide whether a lender will offer a mortgage, whether a deposit source is acceptable, or what a solicitor's final completion statement will contain. Keep a buffer for costs you have not yet quoted and ask your conveyancer and lender for their confirmed figures.
Common mistakes
- Mixing up loan amount and property value, which can distort affordability and LTV.
- Using a headline rate but forgetting fees, insurance, taxes or repayment type.
- Testing only one term length instead of comparing the payment and total cost together.
- Forgetting that a repayment mortgage and an interest-only mortgage produce very different monthly figures.
What to do next
- Run a second scenario with a higher rate or shorter term so you can see the downside clearly.
- Compare the result with an affordability or overpayment calculator before applying.
- Note the monthly payment and total interest for your strongest scenarios before you speak to a broker.
- Check whether a modest overpayment would reduce total interest — use the overpayment calculator next.