変換方法 Currency
Step-by-Step Conversion Guide
Learn to ConvertWhether you're planning a trip, shopping online from foreign stores, or sending money abroad, knowing how to convert currencies is a practical skill. This guide walks you through the math and offers tips for getting the best rates.
理解する Rate Direction
The exchange rate format tells you how to calculate.
Example: EUR/USD = 1.10
This means: 1 EUR = 1.10 USD
Converting EUR to USD
- You have euros, want dollars
- 100 EUR × 1.10 = 110 USD
- Multiply by the rate
Converting USD to EUR
- You have dollars, want euros
- 100 USD ÷ 1.10 = 90.91 EUR
- Divide by the rate
Step-by-Step Conversion Process
Step 1: Find the Current Rate
- Check a reliable source (bank, financial website, converter tool)
- Note which currency is base (first) and quote (second)
- Be aware rates change constantly
Step 2: Identify Your Conversion Direction
- What currency do you HAVE?
- What currency do you WANT?
Step 3: Apply the Formula
- If converting FROM the base currency: multiply
- If converting TO the base currency: divide
Step 4: Account for Fees
- The rate you get may differ from the market rate
- Add any fixed fees to your calculation
Practical Examples
Example 1: Travel Budget
You're traveling to Japan with $1,000 USD.
- Rate: USD/JPY = 150
- Calculation: $1,000 × 150 = ¥150,000
- You'll have 150,000 yen for your trip
Example 2: Online Shopping
Item costs £75 GBP, you pay in USD.
- Rate: GBP/USD = 1.27
- Calculation: £75 × 1.27 = $95.25
- The item costs you $95.25
Example 3: Sending Money
Send $500 USD to receive euros.
- Rate: EUR/USD = 1.10
- Calculation: $500 ÷ 1.10 = €454.55
- Recipient gets €454.55
Converting with Cross Rates
Sometimes you need to convert between two currencies without a direct rate.
Example: EUR to GBP via USD
- EUR/USD = 1.10
- GBP/USD = 1.27
- Convert €100 to GBP:
- First to USD: €100 × 1.10 = $110
- Then to GBP: $110 ÷ 1.27 = £86.61
Or directly: EUR/GBP = 1.10 ÷ 1.27 = 0.866
€100 × 0.866 = £86.60
Accounting for Fees and Spread
The Real Cost of Exchange
The rate you get is never the "mid-market" rate you see online.
Types of Costs
- Spread: Difference between buy/sell rates (1-5% typical)
- Fixed fees: Per-transaction charges
- Percentage fees: % of amount converted
- Hidden markups: Baked into "zero fee" offers
Calculating True Cost
Compare what you receive to the mid-market rate:
- Mid-market rate would give you: €454.55
- You actually receive: €440
- True cost: (454.55 - 440) / 454.55 = 3.2%
Getting the Best Rates
Do
- Compare multiple providers before exchanging
- Use online comparison tools
- Consider dedicated currency services (Wise, Revolut)
- Exchange larger amounts at once (better rates)
- Use no-foreign-fee credit cards for purchases
Don't
- Exchange at airports (worst rates)
- Use hotel exchange services
- Accept "dynamic currency conversion" (pay in your currency)
- Wait until you desperately need cash
通貨コンバーター 変換先ols
Online Converters
- Show mid-market rates
- Good for planning and estimation
- Update in real-time
Bank Apps
- Show your actual rate
- Include fees in the calculation
- Enable direct transfers
Our Converter
- Quick calculations for any currency pair
- Helpful for budgeting and planning
- Compare amounts across multiple currencies
まとめ
Currency conversion follows simple math: multiply or divide by the exchange rate depending on your conversion direction. The challenge is getting a good rate—the spread between buy and sell rates represents your true cost. By comparing providers, avoiding high-fee locations like airports, and understanding how rates work, you can save significantly on international transactions.