Currency Converter Calculator
Convert an amount from one currency to another at a given rate, with the reverse conversion for quick comparison.
輸入資料
計算結果
重點速覽：Converted = amount x rate; reverse = amount / rate. Rate = '1 source currency = how many target'. Example: 1,000 at 7.8 → 7,800; reverse 1,000 / 7.8 ≈ 128.21. Watch the rate direction (take reciprocal if reversed). WARNING: Single mid-rate math; real FX adds spreads/fees; rates move. Education, not advice.
計算公式
換算後金額 = 金額 × 匯率 (匯率 = 1 來源貨幣值多少目標貨幣)。
反向換算 = 金額 ÷ 匯率。
反向換算可理解為:若這筆金額本身是目標貨幣,值多少來源貨幣。
$$換算後金額：$Converted = Amount\times Rate$$$$$反向換算：$Reverse = Amount \div Rate$$$$$示例 (匯率 7.8)：$1000\times7.8=7800$、$1000\div7.8\approx128.21$$$使用說明
- Enter the source amount.
- Enter the rate: 1 source = how many target.
- View the converted target amount and the reverse conversion.
不同金額與匯率下的換算結果
| 金額 | 匯率 (1 來源 = ? 目標) | 換算後金額 (目標) | 反向換算 (來源) |
|---|---|---|---|
| 1,000 | 7.8 | 7,800 | 128.21 |
| 5,000 | 7.8 | 39,000 | 641.03 |
| 1,000 | 0.128 | 128 | 7,812.5 |
理財情境案例
案例一：一筆貨幣換算
假設匯率為 7.8 (即 1 單位來源貨幣 = 7.8 單位目標貨幣),想換算 1,000 單位來源貨幣。
換算後金額 = 1,000 × 7.8 = 7,800 單位目標貨幣；反向換算 = 1,000 ÷ 7.8 ≈ 128.21 單位來源貨幣。
解讀：1,000 單位來源貨幣可換到 7,800 單位目標貨幣。反向換算 128.21 的意思是：若這 1,000 本身是目標貨幣，則值約 128.21 單位來源貨幣。搞清楚匯率方向，是換匯不出錯的第一步。
案例二：匯率方向弄反會差多少？
同樣要把 1,000 單位貨幣換算，但這次匯率報價為 0.128 (即 1 單位來源 = 0.128 單位目標)。
換算後金額 = 1,000 × 0.128 = 128 單位目標貨幣；反向換算 = 1,000 ÷ 0.128 ≈ 7,812.5 單位來源貨幣。
解讀：注意 7.8 與 0.128 其實互為倒數 (1 ÷ 7.8 ≈ 0.128),代表同一組貨幣關係的兩個方向。若把匯率方向弄反 (該乘的變成除、該除的變成乘),1,000 會被錯算成 128 或 7,812.5，相差幾十倍！所以換匯前務必確認：報價到底是『1 來源值多少目標』還是『1 目標值多少來源』。⚠️ 本計算器算的是理論金額，實際兌換時銀行或找換店會加上買賣差價與手續費，換到的錢會比計算值少。
常見問題
How does conversion work, and can the rate direction be wrong?
The core is converted = amount x rate; the easy mistake is the rate's direction. Rate always means '1 unit of X = how many Y'. This tool defines rate as 1 source = how many target. Example: 1,000 USD to HKD, USD source, HKD target, 1 USD = 7.8 HKD → 7,800 HKD. If your quote is reversed (1 HKD = 0.128 USD), take its reciprocal (≈7.8) before entering. The reverse field (amount / rate) helps you check the direction — an absurd result means the direction is flipped.
Why do I get less than the calculator shows?
This uses a single mid-rate; real exchange adds a bid-ask spread (you always trade on the worse side), fees/commissions, credit-card FX or overseas-transaction charges (often 1%-3%), and ATM fees, plus rate movement between quote and execution. Use the result as a baseline, then compare channels by actual amount received.
Any money-saving tips for exchanging?
Compare several channels (banks, changers, e-wallets, cards) by total cost, not just rate. Watch hidden fees — judge by 'amount I get', not the headline rate. Avoid airport/hotel changers (worst spreads). Use low-fee multi-currency accounts where suitable. For large sums, consider splitting to average rate risk, but mind per-transaction fixed fees. Decline DCC (choose local currency) when asked overseas.
Why less than calculated, again?
Because the tool applies your input rate directly (a theoretical amount), while banks/changers/apps apply a bid-ask spread, possible fixed fees, cash-vs-wire gaps, live rate movement, and card FX/overseas fees. Use it to estimate; settle on the institution's actual quote. To lose less, compare channels and favor small-spread, commission-free ones; large exchanges often get better rates.
What are practical saving tips?
Compare total cost (spread + fees), not just 'no commission' claims. Distinguish mid-rate from execution rate. Avoid airports/hotels. Use multi-currency accounts or near-mid-rate services if you exchange often. Watch rate trends and split large non-urgent exchanges. Check overseas card fees and decline DCC (pay in local currency). The calculator gives the theoretical baseline to judge quotes.
相關工具
參考資料
內容審核：香港計算器財經團隊。計算邏輯與公式參考香港金融管理局（HKMA）及投資者及理財教育委員會（IFEC）之個人理財計算指引，結果僅供參考，實際以相關機構公佈為準。