Reduce hours to temp. Help me calculate if better off?

Adamc

I have access to a bank temporary position earning £44 per hour gross. (Excludes NI and tax. There is the option to pay into the NHS pension too). 
My current hourly rate is approx £24.38.

I want to drop a day in my full time employment and pick the equivalent amount of hours up in the temporary position.  

I work 37.5 hours per week with an unpaid lunch hour. I would reduce my hours by 7.5 (one day) and pick these hours up for the hourly rate of £44.

1.) How can I accurately calculate if I am much better off for the time this is available?  

2.) At what point would I go on to the higher rate of tax? Is this when my gross OR taxable wage exceeds £50270?

Adamc

I don't think I would pay student loan on the temporary position as well as my main job. 

I would be foregoing some accrued leave though so difficult to see the true benefit.

I am interested to know the increase in take home pay.

A colleague in the same job has reduced their working days by two and now temps 2 days flexibly which works really well for them but they wouldn't share if better off financially each month/year. 

dave2319

I think your colleague's reluctance to say whether they're better off is probably an indicator that they are!

And am not a tax expert but I think it's very likely to be the taxable wage figure that you don't want to exceed 50,270, rather than the gross. So if you'd be picking up an extra 20 quid an hour for 7.5 of your hours per week, that's 150 quid. Even multiplied by 52 weeks is 7.8k, so shouldn't pose any threat to the 50k threshold.

There's another area of the forum for work and tax though, so it might be best to check here: https://forums.moneysavingexpert.com/categories/work-benefits-business