Buy to Let Calculator

Buy-to-let mortgage rates are calculated on your loan-to-value (LTV) and the duration of the mortgage deal. Usually, the cheapest buy-to-let mortgages are those with the lowest LTV of 60% and shorter deal terms (avoiding the lender’s standard variable rate).

Lenders treat mortgages for a rental property as a higher risk than a residential mortgage. This means buy-to-let mortgages generally have a higher minimum deposit of 20% and come with higher interest rates and fees compared to residential mortgages.

Mortgage lenders usually require your rental income to be at least 125% of your monthly mortgage payments or mortgage interest. Some lenders may require a higher minimum rental income sometimes over 145%. As part of this calculation, lenders will use a managed rate and not your actual mortgage product rate to calculate your monthly buy-to-let mortgage payment – in a lot of cases, this is 5.5%. You will also need to meet the lender’s minimum salary requirements.

A £100,000 buy-to-let mortgage at a rate of 1.39% fixed for two years (60% LTV) with a fee of £1,499 would cost you £10,973.93 over the two-year term. This would be a repayment mortgage over a 25-year term.

You can use three different calculations to find out if your property investment is paying a satisfactory return. These are rental yield, return on investment and cash on cash.

To work out rental yield, you take the annual rent divided by the value of the investment property multiplied by 100.

Rental yield = (Annual rent / property value) x 100

For example, a £250,000 property earning £860 per month in rent would achieve a 4.16% yield.

Your return on investment is calculated by calculating your earnings less your cost of investment, divided by the cost of investment. Then multiplied by 100 to get a percentage.

Return on investment = (Total of earnings – cost of investment) / cost of investment x 100

This calculation is very simplified and is not specific to buy-to-let investments

This calculation allows you to see the return on your initial cash investment less your monthly mortgage payments.

Cash on cash return = (Net annual cash flow/total cash invested) x 100

Cash invested includes any deposit you needed for the mortgage, any additional fees connected to your investment and as any costs for work or refurbishments made to the property.

Net annual cash flow is your annual rental income less your annual mortgage payments.

For example, you invest in £50,000 as a deposit for your buy-to-let mortgage and spend £10,000 in renovations. Your total cash invested in £60,000. You pay £350 per month for your buy-to-let mortgage and receive £860 in rental income. Your net annual cash flow is £6120. Your cash on cash return would be 11.4%.

Rental yield is a measure of your annual return on your buy-to-let investment. You can use it to compare it to the rates of return on other investments such as savings accounts and to check your investment is outperforming inflation.

A good rental yield varies depending on the location of the property due to property costs and the health of the rental market. The top 25 locations for rental yield in the UK currently achieve between 6.9% and 11.99%.*

*Source – Totally Money Buy to Let Yield Map 2018/19.

Finding the right buy-to-let mortgage depends on the circumstances of your property and yourself. You may find that to be eligible for some buy-to-let mortgages that you need to be an experienced landlord rather than a first-time landlord. Some lenders will not accept properties of unusual construction type, including flat and thatched roofs while others may have rules about local authority properties or flats above commercial premises. Some lenders also restrict multiple properties or houses of multiple occupation. 

You can find the right buy-to-let mortgage either by researching the market directly using our comparison table or by speaking to our preferred mortgage broker.