How Compound Interest Grows Your Savings
Compound interest earns you interest on your interest. A $10,000 balance earning 5% annually generates $500 in year one. In year two, you earn 5% on $10,500—that's $525. The gap accelerates every year. After 20 years at 5%, $10,000 becomes $26,533 without adding a single dollar.
The formula: FV = PV × (1 + r/n)^(n×t) + PMT × [((1 + r/n)^(n×t) − 1) / (r/n)]. PV is your current savings, PMT is your monthly contribution, r is your annual return, n is compounding frequency (12 for monthly), and t is time in years. This calculator runs the math month by month so you see exactly when your goal is reached.
How Much to Save Per Month by Goal Amount
| Goal | 2 Years | 5 Years | 10 Years | 20 Years |
|---|---|---|---|---|
| $5,000 | $201/mo | $74/mo | $32/mo | $12/mo |
| $10,000 | $402/mo | $147/mo | $64/mo | $24/mo |
| $25,000 | $1,005/mo | $368/mo | $161/mo | $61/mo |
| $50,000 | $2,010/mo | $736/mo | $322/mo | $121/mo |
| $100,000 | $4,021/mo | $1,472/mo | $644/mo | $243/mo |
Assumes 5% annual return, starting from $0. Starting with existing savings reduces the monthly amount significantly—use the calculator above to see your exact number.
Emergency Fund Guidelines: 3–6 Months of Expenses
Your first savings goal should be an emergency fund covering 3–6 months of essential expenses. Not income—expenses. If you spend $3,000/month on rent, food, insurance, and transportation, your target is $9,000–$18,000.
Start with a $1,000 starter fund, then build to one month, then three. Keep emergency funds in a high-yield savings account—accessible within 1–2 business days, earning interest while you wait. Never invest emergency funds in the stock market.
Who needs 6 months: freelancers, single-income households, anyone in a volatile industry (tech, media, real estate). Who can get by with 3 months: dual-income households with stable jobs and good benefits.
Savings Account Types Compared
| Account Type | Typical APY | Access | Best For |
|---|---|---|---|
| High-Yield Savings (HYSA) | 4.0–5.0% | 1–2 business days | Emergency fund, short-term goals |
| Certificate of Deposit (CD) | 4.5–5.5% | Locked 3–60 months | Known future expenses (wedding, tuition) |
| Money Market Account | 3.5–4.5% | Instant (debit card/checks) | Large balances, check-writing needs |
| Traditional Savings | 0.01–0.5% | Instant | Almost never—switch to HYSA |
| I Bonds (US Treasury) | Inflation-linked | 12-month lockup | Inflation hedge, $10K/year limit |
For goals under 2 years away, a HYSA is almost always the right choice. For goals 2–5 years out, consider a CD ladder. For anything beyond 5 years, you should be investing in index funds, not savings accounts—historically, the S&P 500 returns ~10% annually before inflation.
7 Tips to Reach Your Savings Goal Faster
- Automate transfers. Set up automatic transfers the day after payday. Money you never see in checking is money you never spend. Use our paycheck split calculator to plan your direct deposit allocations.
- Use a HYSA, not your checking account. A $20,000 emergency fund in a 4.5% HYSA earns $900/year in interest. In a 0.01% checking account, that same money earns $2.
- Round up and sweep. Many banks offer round-up programs that sweep spare change into savings. Acorns, Qapital, and bank-native tools automate this.
- Apply the 24-hour rule. Before any non-essential purchase over $50, wait 24 hours. You'll skip about 40% of impulse buys.
- Redirect windfalls. Tax refunds, bonuses, birthday money, side-hustle income—route at least 50% directly to your goal. One $3,000 tax refund equals 6 months of $500/month savings.
- Cut one subscription per month. The average American spends $219/month on subscriptions. Cancel the ones you haven't used in 30 days. That's instant cash flow freed up.
- Increase contributions with every raise. Got a 3% raise? Increase your savings rate by 2% and keep 1%. You'll never feel the difference but your savings will compound dramatically.
To budget your entire income around savings goals, try the 50/30/20 budget calculator. For planning how to split your paycheck between spending and savings accounts, use the paycheck split calculator.