Ruth Canham-James

OTJ Hours Calculation for Part Time



I have a really straightforward calculation for increasing minimum duration for Part Time Apprentices, and an easy calculation for working out OTJ taking into account statutory 28 days leave, but I'm struggling with working out the minimum OTJ for PT. The guidance just says;

P46 When calculating the required amount of off-the-job training, the apprentice’s statutory leave entitlement must be deducted. Employees who work a 5-day week receive at least 28 days paid annual holiday (this is the statutory leave entitlement referred to in this paragraph and is the equivalent of 5.6 weeks of holiday). You must pro-rata this for part time workers.

Pro-rata how? We have an apprentice that does 21 hours a week over 4 days. Do we assume 80% as she works 4 days out of 5, or 70% as that’s the percentage of the full time minimum of 30?


Hours a week = 21

Days a week = 4

Hours a day = 5.25

Duration in weeks = 78

Days worked = 312

Hours worked = 1,638

Statutory holiday if full time = 42

Statutory holiday pro rata at 80% = 33.6

Statutory holiday pro rata at 70% = 29.4


312 – 33.6 = 278.4

312 – 29.4 = 282.6


278.4 x 5.25 = 1,461.6

282.6 x 5.25 = 1,483.65


1,461.6 / 5 = 292.32

1,483.65 / 5 = 296.73


I'm really struggling to get my head around this one.


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My spreadsheet does it as [duration in weeks]/52*5.6 rather than thinking about how many days a week they work... So would be 8.4 weeks for a 78 week duration.

So my calc would be:

([duration in weeks] - [leave in weeks]) x ([hours per week] x 0.2)

(78-8.4) x (21 x 0.2) = 292.32




Martin West

The calculation for the holiday entitlement is in hours and you deduct this from the total hours, 20% of this is the minimum OTJ hours required.

holiday entitlement= Statutory Annual Leave Entitlement (Wks)* Apprentice normal working hours per week (Hrs) *(Weeks On Programme (Wks) (Duration)/52)

Total hrs less holiday entitlement 176=1461 hrs x 20% = 292.3

You will note the holiday entitlement calculation does not include the number of days they work but it is pro rata already as the days/Wk they work is derived.



Ruth Canham-James

Thanks Martin West and Steveh, that does make sense. I wish they'd just say that explicitly in the rules rather than just "pro-rata". The thing we've discovered in all this is that average weekly hours needs recording in our data. Our software doesn't have a place for this, as it's not an ILR field, but it's critical for getting calculations right. It's especially important for term time only, who always end up being part time. We still have to calculate the average weekly hours manually for TTO, but that's straightforward.

Tony Green


Useful discussion - thanks :) However...

I get the calculations for the OTJ hours where the length is extended due to <30 hours per week…

…BUT as the rule for part-time working seeks to extend the length to effectively make it equivalent to a FT (30 hours plus) apprenticeship, is it right (fair?) that the calculation means more OTJ for the part-time one than for the ‘equivalent’ full-time one?


  • a ‘FT’ (30 hours) 12 month programme has a minimum OTJ of 278 (calculation works fine)
  • a ‘PT’ (16 hours) 23 month programme (extended as per guidance) has an OTJ of 285 hours (same calculation)

I know the difference isn’t huge in this example, but the longer the durations, the greater the difference…am I overthinking this? :)

Martin West

You will get the discrepancy as you are working in months when it should be weeks, it should be 30 ft hrs/16 pt hrs = 1.875 ratio to extend the 52 weeks to 97.5 weeks and this produces the same OTJ hours 278.

Tony Green

Thanks Martin - think I've cracked it now with that help :)