Weighted Average Cost Calculator
If you bought the same item several times at different prices, enter each purchase’s quantity and unit price to get the weighted average unit cost, the total stock value and the cost of what you sold at that average.
- Total quantity350.00 units
- Total purchase cost19,750.00 ₺
- Lowest unit price50.00 ₺
- Highest unit price60.00 ₺
- Simple average price (unweighted)55.00 ₺
Purchases
How it is calculated
A weighted average counts each purchase price by the quantity bought, which a simple price average does not. Under TMS 2 Inventories (para. 25) cost is assigned by first-in first-out (FIFO) or weighted average cost; para. 27 lets the average be worked out periodically or at each new delivery, and Art. 274 of the Tax Procedure Law values goods at cost. This tool combines every purchase you enter into one (periodic) average. For a running average, find it for the purchases before a sale, then enter the stock left together with the next purchase. The same sum tracks the average cost of shares, currency or gold bought in several lots; for the tax on securities gains, though (Income Tax Law provisional Art. 67/1), the purchase price follows first-in first-out, and a weighted average may be used only for trades within the same day.
Average cost = Σ(Quantity × Unit price) ÷ ΣQuantity; Cost of goods sold = Units sold × Average cost- Multiply each purchase’s quantity by its unit price.
- Add up the amounts and divide by the total quantity.
- Multiply the units sold by the average; the rest is valued at the same average.
Example
100 × ₺50 = ₺5,000, 200 × ₺60 = ₺12,000, 50 × ₺55 = ₺2,750. Total ₺19,750 ÷ 350 = ₺56.43. The simple average of the prices would be ₺55; the large ₺60 batch pulls the average up.
Frequently asked questions
Why is it not the average of the prices?
Because each price counts by its quantity. 10 at ₺100 and 90 at ₺50 average ₺75 by price, but the weighted average is (1,000 + 4,500) ÷ 100 = ₺55.
Can I use it for share purchases?
For your own records, yes: enter each lot’s quantity and price (with commission); if you enter the units sold, the average cost of the rest stays the same. It is not the tax method, though: under Income Tax Law provisional Art. 67/1, banks and brokers set the purchase price in the withholding base “using the first-in first-out method”, and “the weighted average method may be used for transactions within the same day”. So the cost used for tax on shares bought on different days follows FIFO and can differ from the average here.
Does a sale change the average?
Not with a weighted average: what is sold and what is left are valued at the same average, which changes only with a new purchase. Under FIFO the earliest units count as sold first, so the unit cost of the rest can change.
Source
- KGK, TMS 2 Inventories (2026 set) paras. 25 (FIFO or weighted average) and 27 (weighted average: periodic or at each delivery)
- Income Tax Law No. 193, provisional Art. 67/1, second paragraph (amended 22 Dec 2005, 5436/14): purchase price in the withholding base by first-in first-out; weighted average allowed for same-day trades
- Tax Procedure Law No. 213, Art. 274 (goods are valued at cost)