Worth it to pay missing pension (UK)?

[Roger Van Zant]

I was looking at my UK pension forecast online just now.
I pay Class 2 NI contributions monthly from Japan.
I am forecast to get 180.71 per week from 12 October 2046.
By this date I will have paid in 34 years' worth of contributions.
I have already paid in 10 full years, and have 18 years of missing or non-full contributions.
https://ibb.co/KLwNmmr

Any missing years I wish to backpay will cost me 824.20.
https://ibb.co/pdG5PDc

The maximum I can increase my pension to would be 185.15 per week.
185.15 - 180.71 = GBP4.44 weekly shortfall as things currently stand.

So, I could backpay one year at 824.20 to bring my total contributions to 35 years, in order to get an extra 4.44 per week.
Over a year this would be : 4.44 x 52wks = GBP230.88 extra per year.

824.20 (backpay) / 230.88 (extra to be gained) = 3.57 (so it would take me over 3.5 years to get back the 824.20).

I made an Excel sheet to see how different exchange rates would affect the amount I will receive (roughly) in Japanese yen.
https://ibb.co/d22LHFJ

Is it worth me paying this one year of backpay?
Has anyone else been in a similar situation?

Thanks!

[beanhead]

If you have got the money, sure, do it. The break-even seems short enough to make it worthwhile (and of course Professor Tanaka tells us that this is not the way to view pensions anyway )
If you don't have the spare cash, don't worry about it. It won't make a huge difference either way.