Your car needs new tires. Is that an emergency? It feels like one when the bill arrives, but tires wear out on a schedule. You could have seen it coming, and that's the whole difference between these two kinds of savings.
The short answer
A sinking fund is money you save on purpose for a known future cost. An emergency fund is money you keep for costs you can't predict.
| Sinking fund | Emergency fund | |
|---|---|---|
| Purpose | Planned costs | Surprises |
| Examples | Gifts, tires, insurance | Job loss, medical bills |
| Target | The cost of the item | 3 to 6 months of expenses |
| When you spend it | On the due date | Only when you must |
Why you need both
If you only keep an emergency fund, every annual bill takes a bite out of it. You pay the insurance premium, replace the washing machine and buy holiday gifts, and by January your safety net is half gone. Then a real emergency hits.
Sinking funds protect the emergency fund. They turn big, lumpy bills into small monthly amounts you barely notice.
How to set up a sinking fund
Pick one cost that caught you off guard last year. Write down how much it was and when it's due next. Divide the amount by the months you have left.
A $900 insurance premium due in nine months needs $100 a month. The sinking fund calculator does this for several funds at once and gives you a single total per paycheck.
Which one should you fund first?
Build a small emergency buffer first. Many people aim for one month of essential expenses to start. Then split new savings between the emergency fund and your two or three most painful sinking funds.
Once the emergency fund covers three to six months of expenses, send most new savings to sinking funds and long term goals.
Where sinking funds fit in your budget
In a 50/30/20 budget, sinking funds usually sit in the 20% savings bucket. In a zero based budget, each fund gets its own line, just like rent.
Keep the money somewhere separate from your daily spending account. A savings account with named sub accounts works well. If you can see the balance grow under a label like "car repairs", you're far less likely to raid it for a weekend away.
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