Please could somebody work this out for me

[tiddlypool]

because I'm too mathematically challenged to do it

We took out a mortgage for £135k earlier this year, 22 year term. How much would we have to overpay monthly if we wanted to pay it off in, say, ten years?

TIA

without getting a calculator out would it be very simplistic of me to say double the amount you're currently paying?

Depends on your interest rate

Or using this tool at 5% you would need to pay £1450 a month.