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.)



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


Kevin Kim said...

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


Anonymous said...

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

Four weeks rarely equals one month.

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.