--- title: "Miles & Kilometres" description: "Convert between miles and kilometres using the approximate relationship (5 miles ≈ 8 km)" canonical: https://lightmysky.com/learn/mathematics/miles-and-kilometres-mt_3tPI0HqqcN source: https://lightmysky.com/learn/mathematics/miles-and-kilometres-mt_3tPI0HqqcN.md retrieved: 2026-10-19 --- > **Agent view.** This is the Markdown twin of the page, for tools and assistants. > When to use this site, and the call that answers each job: https://lightmysky.com/agent-instructions.md > API description (OpenAPI 3.1): https://lightmysky.com/openapi.json · Authentication: https://lightmysky.com/auth.md > Pricing: https://lightmysky.com/pricing.md · Catalog: https://lightmysky.com/llms.txt · Full catalog: https://lightmysky.com/llms-full.txt > Every machine-readable file on this domain: https://lightmysky.com/.well-known/ai-catalog.json > Ask for Markdown with `Accept: text/markdown`, a `.md` address, or `?mode=agent`. # Miles & Kilometres Convert between miles and kilometres using the approximate relationship (5 miles ≈ 8 km) Subject: Mathematics · Area: Measurement · Ages 10 to 11 Page: https://lightmysky.com/learn/mathematics/miles-and-kilometres-mt_3tPI0HqqcN ## Ready when they can - Convert 40 miles to approximately 64 km - Explain why the conversion factor between miles and km is approximately 1.6 - Use the miles↔km relationship to compare a 10 km race with a 6-mile run ## Lesson: Miles and Kilometres Distance can be measured in two different units: miles and kilometres. Road signs in the UK and the US use miles. Almost everywhere else, and most science, uses kilometres. Since both units measure the same kind of thing, you can convert between them. *(drawing: 5 miles and 8 kilometres cover roughly the same distance.)* Where does the number 1.6 come from? Divide the two sides of the rule: 8 km ÷ 5 miles = 1.6. That is why multiplying a number of miles by 1.6 gives a good estimate in kilometres. The 5-to-8 rule and the times-1.6 rule are really the same idea. **Example.** How far is 40 miles in kilometres? Split 40 miles into groups of 5: that makes 8 groups. Each group is about 8 km, so 8 groups make 8 × 8 = 64 km. Forty miles is about 64 kilometres. **Tip.** When you compare distances given in different units, convert them to the same unit first. A 6-mile run is about 6 × 1.6 = 9.6 km, so it is a little shorter than a 10 km race. **Recap.** 5 miles is about 8 km, so multiply miles by 1.6, or scale in groups of 5, to estimate kilometres. ## Practice 18 questions on this page, each with its working shown. ## Needs first - [Metric & Imperial Conversion](https://lightmysky.com/learn/mathematics/metric-and-imperial-conversion-mt_p6MhZJYYPN) - [Multiplying decimals by whole numbers](https://lightmysky.com/learn/mathematics/multiplying-decimals-by-whole-numbers-mt_SoDP1fSQEB) ## Opens up - [Unit Conversions](https://lightmysky.com/learn/mathematics/unit-conversions-mt_tpT9brpI6D)