This is calculated after-the-fact. The final effective exchange rate that I got is based on initial starting cash, and then on subsequent transactions made against my bank account and credit card.
All dollars are Australian.
- KVB Kunlun, before the trip
$1995.05 -> 170,000 yen
- 85.211 JPY/AUD
- ATM withdrawal on 2012-03-07
$490.22 -> 40,000 yen (AUD value includes a $19.13 bank fee for the withdrawal)
- 81.596 JPY/AUD
- ATM withdrawal on 2012-03-10
$481.80 -> 40,000 yen (AUD value includes a $18.89 bank fee for the withdrawal)
- 83.022 JPY/AUD
- ATM withdrawal on 2012-03-11
$243.40 -> 20,000 yen (AUD value includes a $11.94 bank fee for the withdrawal)
- 82.169 JPY/AUD
- JR East shinkansen ticket on 2012-03-09
$61.70 -> 5,240 yen ticket value (AUD value does not include bank fees, not yet confirmed)
- 84.927 JPY/AUD
- As an estimate, $64.00 would make it 81.875 AUD/JPY
Now calculate the weighted average. I'll just be lazy and do Sum(all JPY values) / Sum(all AUD values)
170,000 + 40,000 + 40,000 + 20,000 270,000 ------------------------------------------ == -------------- == 82.514 1995.05 + 490.22 + 481.80 + 243.40 + 61.70 3,272.17 For reference, increasing the denominator by a few AUD, to 3275, reduces the exchange rate to 82.443