Worked example
Reviewing a Bitcoin purchase history
Fictional data. These three purchases are made up to show the method. They are not real prices, not a real person's history and not an exchange export. A paid review of a real purchase history is not available yet — this page only shows what one would calculate, and no exchange's export format is supported yet.
Proposed price: AED99 once. Not available to purchase yet.
When you buy Bitcoin repeatedly, the question isn't what one purchase cost. It's: across everything I spent, how much bitcoin did I actually get? Here is that calculation for three completed purchases.
The purchases
| Purchase | Date | AED paid | Net BTC | AED per BTC |
|---|---|---|---|---|
| EXAMPLE-01 | 2026-09-01 | AED 2,000.00 | 0.00495000 BTC | AED 404,040.40 |
| EXAMPLE-02 | 2026-09-08 | AED 3,000.00 | 0.00720000 BTC | AED 416,666.67 |
| EXAMPLE-03 | 2026-09-15 | AED 5,000.00 | 0.01200000 BTC | AED 416,666.67 |
The totals
- Total spent: AED 10,000.00
- Total bitcoin received: 0.02415000 BTC
- Effective price across the history: AED 414,078.67 per BTC
- AED fees identified inside those amounts: AED 50.00 — already included in the total above, so not added again
- BTC fees deducted: 0.00000000 BTC — this fictional history defines them as zero. In a real history, BTC fees are shown in BTC and are already taken out of the net bitcoin, so they are never subtracted twice or converted to AED without a reliable price.
All three are completed purchases delivered to the same place (an exchange balance). A review only combines purchases that ended up in the same place; quotes that were never executed are not purchases.
Why a simple average gets it wrong
Averaging the three per-purchase prices gives AED 412,457.91 per BTC. That treats a AED 2,000 purchase as if it mattered as much as a AED 5,000 one. The correct figure divides the total AED by the total bitcoin — AED 414,078.67 — which weights each purchase by how much bitcoin it actually bought. On a real history, with many purchases of different sizes, the gap between the two can be much larger.
What a real review has to handle
- Separating deposits and transfers from actual purchases, so money moving around isn't counted as buying.
- Using net BTC after any fee charged in bitcoin, not the gross amount.
- Including the funding side — how the AED got onto the exchange — which a trade export often leaves out.
- Flagging missing data instead of presenting a partial history as the full cost.
For a single quote, the free Bitcoin cost check does this arithmetic in your browser.
Educational illustration using fictional figures. Not investment, financial, tax or legal advice, and not a tax calculation.