How to Learn the Metric Conversions
The metric system is built on tens, which makes conversions clean once you know the anchor facts: 1000 metres in a kilometre, 100 centimetres in a metre. Add a few metric-to-imperial approximations and you can convert almost anything. This deck covers both.
There are 12 cards in the deck below. You can read through them, practise them right here with the flip-card player, and then save the deck to study properly with spaced repetition — the method that makes them stick for months, not minutes.
Why the metric conversions is hard to memorize (and the fix)
People know the system is base-10 but forget which way to multiply, and the metric-imperial bridges (miles, pounds, inches) are pure memorization.
The fix is active recall plus spaced repetition. Instead of re-reading the list (which feels productive but barely works), you test yourself — pull each answer out of memory — and you review each card on a schedule that stretches over time. Every time you successfully recall a fact, the memory gets stronger and the next review is pushed further out. That's how you go from "I saw it once" to "I just know it."
The fastest way to learn the metric conversions
- Break it into small batches. Learn the within-metric facts first (they are all powers of ten), then the metric↔imperial approximations separately.
- Test, don't re-read. Look at the question, say the answer out loud before flipping the card. The little struggle to recall is what builds the memory — a smooth re-read does almost nothing.
- Review on a schedule. Spaced repetition shows you each card right before you'd forget it. Get one right and it comes back in a few days, then a week, then a month. Miss one and it comes back sooner.
- Keep sessions short and daily. Five to ten minutes a day beats a two-hour cram every time. Consistency is the whole game.
One fact per card. For metric↔imperial, learn them as approximations (1 inch ≈ 2.54 cm, 1 mile ≈ 1.6 km) — that is all you usually need.
The full deck: the Metric Conversions
Here's every card in the set. Practise them above, or save the deck and let spaced repetition schedule your reviews automatically.
| Conversion | Equals |
|---|---|
| How many metres in a kilometre? | 1000 |
| How many centimetres in a metre? | 100 |
| How many millimetres in a metre? | 1000 |
| How many millimetres in a centimetre? | 10 |
| How many grams in a kilogram? | 1000 |
| How many millilitres in a litre? | 1000 |
| How many centimetres in a kilometre? | 100,000 |
| Approximately how many centimetres in an inch? | 2.54 cm |
| Approximately how many kilometres in a mile? | ≈ 1.6 km |
| Approximately how many pounds in a kilogram? | ≈ 2.2 lb |
| Approximately how many litres in a US gallon? | ≈ 3.79 L |
| How many square metres in a hectare? | 10,000 |
Save this deck and actually remember it
Create a free account, keep this 12-card deck, and we'll schedule every review at the perfect moment. First deck free forever — no credit card.
Study this deck free →FAQ: learning the metric conversions
How long does it take to learn the metric conversions?
Most people can lock in the metric conversions within one to three weeks of short daily sessions. With spaced repetition doing 10–12 cards a day, you'll recognise them within days and recall them reliably within a couple of weeks.
What's the best way to memorize the metric conversions?
Active recall plus spaced repetition. Test yourself instead of re-reading, and review on a schedule that spaces the cards out over time. Flashcards are built for exactly this — which is why the deck above is the fastest path.
Is this deck free?
Yes. You can practise all 12 cards on this page for free with no account. Sign up (also free) to save the deck and let spaced repetition schedule your reviews so it sticks long-term.