How quickly can we pay off our mortgage?

[Chocolatecakeisthebest]

I am absolutely awful at finances and do not understand mortgages (sorry in advance!) But I was wondering if anyone could help me work out how quickly we could pay the mortgage off. I put my numbers in an online calculator but it said it only takes 8 years off my mortgage and I am not sure how.
So... mortgage is £1300 for 30 years. Interest rate is 5.3% fixed for 4 years.
I can overpay by 10% per year during this fixed period.
I can save around £30,000 per year, and most will be used to overpay the mortgage.
How quickly can I pay my mortgage off with these figures?
Thank you so much for any help!

lowe monthly amount is fantastic if you need a breather for a car repair for example.

even if the term doesn't shorten on paper, in reality the more you overpay the more quickly it could be paid in full.

also check if the rate you are allowed to overpay is based on the current or the initial balance.

If you can put away 30k per year (£120k in 4 years). Pay 10% (£22k) off year 1, £19.8 year 2 and so forth.... then you pay off the remainder when your mortgage expires at the end of year 4 meaning you gave a mortgage now of £100k when you re-mortgage.

@Chocolatecakeisthebest you can usually choose to leave the payments the same as otherwise it won’t reduce the time taken. However, because you are planning on saving £30000 a year and aiming to use savings to pay it off there would be a variety of options at the end of the current deal (new smaller mortgage, carry on as you were on whatever your deal turns into, make several large payments or a combination of those, etc)

Note
A regular saver with an advertised interest rate of 7%
Will actually only pay you 3.5% at the end of the term ( this is due to how compound interest works)

You would be better off putting tour savings into an account that pays 5% or a tax free ISA

trying to find enough regular savers to put away £2500 per month would be a mighty task

In real terms an ISA paying 5.2% is worth 7% and considering the OP can afford to save £30k a year I would guess they are in a 40% tax bracket - but that is a guess.

Also as another note - don't keep more than £85k in one account - spread your eggs, but £85k is the limit for getting back if the bank goes bust

Plum ISA 5.17%
Virgin, Zopa, Raisin similar interest rates & tax free

@summer555 what would be your investment recommendation (as someone new to it?)

This. And in the meantime put savings into a high rate fixed account.

It really depends on how much risk you're willing to take.

Speak to your lender and keep your payments the same, thats what we do