Tuesday, August 30, 2005

how to calculate overtime pay 2: something weird

This is all very strange. I've been crunching numbers for a good part of the evening, and something's not right.


(SUBJECT, scheduled time, elapsed time x #times/week = hrs per week)

TOPICS, 7:40-8:50 = 1:10 x 4 = 4:40
CORE 2, 10:50-12:00 = 1:10 x 4 = 4:40
INTENSIVE 2, 1:10-2:35 = 1:25 x 4 = 5:40
INTENSIVE 5, 2:45-4:10 = 1:25 x 4 = 5:40
DRAMA, 4:20-5:50 = 1:30 x 1 = 1:30

ONE-WEEK TOTAL = 22:10 (22hrs, 10mn)


According to my contract, overtime is calculated as W20,000 per hour over 18 hrs/week worked. This is where the office got its 72 hrs/month figure.

For July, I worked:
Week 1 = 22:10 (i.e., 4:10 hrs overtime)
Week 2 = 22:10 (i.e., 4:10 hrs overtime)
Week 3 = 22:10 (i.e., 4:10 hrs overtime)
Week 4 = 22:10 (i.e., 4:10 hrs overtime)

Total July hours = 88:40 - 72 = 16:40
JULY OVERTIME PAY = 16:40 x 20,000 = W333,333
TOTAL NET PAY FOR JULY = 2,200,000 + 333,333 = W2,533,333

By this reckoning, I received too much overtime pay.

And now-- August:

Week 5 = 11:50 (missed 2 days for break; 0 overtime hours)
Week 6 = 22:10 (i.e., 4:10 hrs overtime)
Week 7 = 18:00 (1 day missed for break, 1 class made up; 0 hrs overtime)
Week 8 = 22:10 (i.e., 4:10 hrs overtime)

Total August hours = 74:10
AUGUST OVERTIME (a) = 74:10 - 72 = 2:10 (if calculated by month)
AUGUST OVERTIME (b) = 8:20 (if calculated week by week)

Notice a discrepancy? Makes a big difference whether you calculate by week or by month.

August overtime is EITHER
(a) 2.16667 x 20,000 = W43,333... or
(b) 8.33333 x 20,000 = W166,667

Note these proportions:

74.17 / 88.67 = 83.6%
(i.e., My Aug. hrs were 83.6% of my July hrs)

166,667 / 333,333 = 50%
(i.e., My Aug. overtime pay is 50% of my July overtime pay)

2,366,667 / 2,533,333 = 93.4%
(i.e., My pay for Aug is 93.4% of my pay for July)

I guess it all depends on how you play with the numbers. One could draw the conclusion that the office miscalculated in my favor, which is fine. But something still feels funny.

13.5 out 16 days in August is 84%... August overtime should, ideally, also be 84%, should it not? The only thing I can conclude is that, by substracting a fixed number of hours each month instead of working the matter proportionately, the overtime calculation gets skewed. By that warped formula, the office did give me too much, but it's still a formula that shortchanges me. Note, though, that the only way to arrive at a number close to the W220,000 figure given in my previous post is to calculate week by week, not substract 72 hours from the total number of hours worked in a month.

Any accountants out there have any input? Am I engaging in fuzzy math?

(By the way, the above calculations are all gross, not net.)



hardyandtiny said...

Isn't 16.40 X 20,000 = 328,000?

I need more time to figure all of this out. let me see......

Kevin Kim said...

True, but I wrote 16:40, not 16.40-- i.e., 16 hours and 40 minutes, which would be about 16.666667 hours in decimal terms.

16.666667 hours x W20,000 =
approx. W333,333.333


hardyandtiny said...

Okay, I was wrong.
250 minutes of overtime 4:10 hours should equal W83,333.333. So, 4 X 83,333.333 = 333333.332
now per day is then, 83,333.333/4 = 20,833.33325
so 13 x 20,833.33325 = W270,833.3225
okay now let me see what I don't understand here.

hardyandtiny said...

2.10 August is 43,333 OT. okay..next post

hardyandtiny said...

I would have to go with the 8.20 for August at 166,667. where's the 220,000 coming from? I don't get it!

Kevin Kim said...

I think the lady miscounted the number of hours I worked-- both months.


hardyandtiny said...

If the contract says W20,000 per hour over 18 hrs/week worked. Then why isn't August 8.20 extra? Hmm, your pizza analogy is not helping me, guess I'll have to read it five more times.

hardyandtiny said...

July looks good to me. August is off.
I'm not boasting but uh, just so ya know. I had a semester of accounting at Westchester Community College in 1981.

Anonymous said...

What's your pay cycle? Are you paid monthly/twice monthly or every other week?

Four weeks rarely equals one month.

Sperwer said...


I think you're making yourself crazy with the arithmetic, which isn't the issue.

The problem revolves around what the terms of your contract are.

Are you entitled to overtime @ the stipulated rate for all time in excess of 18 hours per week? Or is the deal that you get overtime for all hours in excess of 72 hours/month?

Therein lies the difference.

What's the contract say?

My guess is that the contract only says overtime for time in excess of 18/week.

But because you're paid on a monthly basis, the powers that be are interpeting it to mean something like "OT for time over 18/week, provided that you work at least 72/month for your base salary."

If I'm right, and I understand your schedule, it means you're effectively getting euchered out of what otherwise might have seemed like paid days off because of legal holidays.

Depnding on what the contract says, this might provide grist for a labor board complaint - assuming you don't want to work @ Smoo any more.

The alternative would be to try to talk them through it in the hopes of fixing things up for the next contract term, but that could be tricky if you feel stringly that you've been had, because you still might make it confrontational.

Kevin Kim said...


The contract calculates everything according to weekly hours and pay, so yeah, something doesn't feel right.

I won't drive myself crazy. I've asked the office to give me an itemized printout of my pay every month from now on, and they've said OK. Knowing how pay is calculated makes for fewer surprises, though it seems the office has a penchant for fudging hours. That tendency worked in my favor-- this time around. Next time, who knows?

Funny... teachers can access their pay records, but the records only display itemized deductions. Pay isn't displayed as itemized (i.e., hours worked times pay rate), but simply shown as the lump-sum total.


Accounting?? But all numbers are the same concept! How is accounting possible? (Sorry, folks; inside joke.)


Good point.