Daily Compound Interest Calculator
Calculate daily compound interest with daily or annual rates, optional reinvest %, extra deposits, and weekend exclusion. Free chart + snapshots — not investment advice.
Results · USD
Future value
Ending invested balance
- Total interest generated
- $3,293.44
- Total deposits
- $1,000.00
- Effective growth
- 329.34%
- Compounding days
- 365
Principal + additional deposits
(FV + cash withdrawn − total deposits) ÷ total deposits
All 365 calendar days
Balance over time· 365 compounding steps
Swipe chart horizontally if needed →
Periodic snapshots· 14 rows
- Period
- Day 1
- Balance
- $1,004.00
- Interest (cum.)
- $4.00
- Withdrawn
- $0.00
- Extra deposits
- $0.00
- Period
- Day 30
- Balance
- $1,127.23
- Interest (cum.)
- $127.23
- Withdrawn
- $0.00
- Extra deposits
- $0.00
- Period
- Day 60
- Balance
- $1,270.64
- Interest (cum.)
- $270.64
- Withdrawn
- $0.00
- Extra deposits
- $0.00
Showing 3 of 14 rows — swipe the schedule below for the full table.
| Period | Balance | Interest (cum.) | Withdrawn | Extra deposits |
|---|---|---|---|---|
| Day 1 | $1,004.00 | $4.00 | $0.00 | $0.00 |
| Day 30 | $1,127.23 | $127.23 | $0.00 | $0.00 |
| Day 60 | $1,270.64 | $270.64 | $0.00 | $0.00 |
| Day 90 | $1,432.30 | $432.30 | $0.00 | $0.00 |
| Day 120 | $1,614.53 | $614.53 | $0.00 | $0.00 |
| Day 150 | $1,819.94 | $819.94 | $0.00 | $0.00 |
| Day 180 | $2,051.48 | $1,051.48 | $0.00 | $0.00 |
| Day 210 | $2,312.49 | $1,312.49 | $0.00 | $0.00 |
| Day 240 | $2,606.70 | $1,606.70 | $0.00 | $0.00 |
| Day 270 | $2,938.34 | $1,938.34 | $0.00 | $0.00 |
| Day 300 | $3,312.18 | $2,312.18 | $0.00 | $0.00 |
| Day 330 | $3,733.58 | $2,733.58 | $0.00 | $0.00 |
| Day 360 | $4,208.59 | $3,208.59 | $0.00 | $0.00 |
| Day 365 (end) | $4,293.44 | $3,293.44 | $0.00 | $0.00 |
Educational estimates · not financial advice · free, no signup
How this was calculated
Daily rate mode: A grows as balance ← balance + interest each day with A_day = balance·r. Annual mode uses r_daily = r_annual/365. Partial reinvest keeps reinvest% of each day's interest invested and withdraws the rest as cash. Deposits are added at end of period. Exclude weekends compounds Mon–Fri only within the calendar span.
Want more detail? Full formula notes & FAQs ↓
Detailed guide
What it is, how to use it, how to read the numbers, common mistakes, a worked example, formulas, and FAQs.
What this calculator is
Daily compound interest credits earnings every day so each day’s interest can itself earn interest. Banks often quote daily compounding on savings, CDs, and money-market products; some trading and financing examples use daily rates too — usually with far higher risk. MyCalcsWorld’s Daily Compound Interest Calculator is a complete day-by-day planner: pick a daily rate or an annual rate divided by 365, set a horizon in years + months + days, open More options for reinvest %, daily or monthly deposits, and weekend (business-day) filtering. Results highlight future value first, then interest, deposits, cash withdrawn, effective growth, a balance-over-time chart, and periodic snapshots. Format money in USD, INR, EUR, and other codes with the currency picker. Illustrative only — not investment advice. Extreme daily percentage rates can imply severe risk of loss beyond your principal.
When to use / who it helps
- Comparing a savings or money-market product that compounds every day against a brochure quote.
- Modeling what happens if you reinvest only part of each day’s interest and take the rest as cash.
- Adding a daily or monthly contribution on top of an existing balance.
- Exploring weekday-only compounding for educational trading/financing calendars (not a broker).
- Checking a worked A = P(1+r)^t example with a chart and snapshot table beside the numbers.
How to use
Steps
- Enter the starting principal and pick your display currency if you like.
- Choose Daily rate (%) or Annual rate (%) → ÷365, then enter the rate.
- Set years, months, and extra days (horizon = years×365 + months×30 + days).
- Open More options only if you need them: reinvest %, deposits, or weekend skip.
- For deposits, choose Daily or Monthly, then enter the deposit amount.
- Read the big future-value result first, then secondary totals, chart, and snapshots.
How to interpret results
- Future value is the invested balance at the end — it excludes cash you already withdrew when reinvest < 100%.
- Total interest generated counts all interest before splitting into reinvested vs withdrawn.
- Effective growth divides net gain (FV + withdrawn − total deposits) by total deposits.
- Compounding days shrinks when weekends are excluded even though the calendar span is unchanged.
- Charts downsample long horizons; the snapshot table keeps periodic checkpoints you can scan quickly.
Common mistakes & gotchas
- Treating a daily % the same as an annual % — 0.4% per day is enormous versus 0.4% per year.
- Forgetting that Future value excludes cash already withdrawn when reinvest is below 100%.
- Expecting weekend exclusion to remove public holidays (this tool only skips Saturday/Sunday).
- Entering deposits while Additional deposits is still set to None — open More options and choose daily or monthly.
- Assuming the currency picker converts foreign exchange; it only changes display formatting.
Worked example
Worked example — $1,000 at 0.4% per day for 365 days
- Principal P = 1000; daily rate r = 0.4/100 = 0.004; t = 365 days; reinvest = 100%.
- Closed form: A = P(1+r)^t = 1000 × (1.004)^365.
- (1.004)^365 ≈ 4.2934377972993, so A ≈ 4293.44.
- Interest ≈ 4293.44 − 1000 = 3293.44.
- Enter the same numbers in Daily rate mode with 1 year (365 days) to mirror this result in the live tool.
Result: About $4,293.44 future value and $3,293.44 interest after 365 daily compounds at 0.4%/day (illustrative — such a daily rate is extremely high versus typical savings products).
Want these demo numbers in the form? Tap Try example above the Calculate button.
How to calculate / formula
Daily rate mode: A grows as balance ← balance + interest each day with A_day = balance·r. Annual mode uses r_daily = r_annual/365. Partial reinvest keeps reinvest% of each day's interest invested and withdraws the rest as cash. Deposits are added at end of period. Exclude weekends compounds Mon–Fri only within the calendar span.
Frequently asked questions
What is daily compound interest?
Interest is calculated and credited every day on the current balance, so previously earned interest can earn more interest. More frequent compounding grows a balance faster than the same nominal rate compounded monthly or annually.
What is the daily reinvest rate?
It is the percentage of each day’s interest you keep invested. At 80% reinvest, 20% of that day’s interest is treated as cash withdrawn and no longer compounds. Example: $5,000 at 0.5%/day earns $25 on day one; 80% reinvest adds $20 to the balance ($5,020) and withdraws $5 cash.
How does excluding weekends work?
The horizon is still a calendar span (years×365 + months×30 + days), but interest (and daily deposits) apply only Monday–Friday. A 365-day span therefore compounds on roughly 261 business days depending on the start weekday — useful for weekday trading calendars, not typical bank savings.
When are additional deposits applied?
At the end of each period: daily deposits after that day’s interest on compounding days; monthly deposits every 30 calendar days. They then participate in later compounding.
Which formula should I use for an annual rate?
With full reinvestment and no deposits, A = P(1 + r/365)^(365·T) for T years of daily calendar compounding. This tool’s Annual mode uses r/365 each calendar (or business) day in the day-by-day engine so reinvest and deposits stay consistent.
Is this for trading or margin interest?
You can explore daily % scenarios educationally, including ones traders discuss for financing or marked-to-market gains, but leveraged trading can lose more than your principal. This page is not a broker, does not include fees/spreads, and is not investment advice — speak with a qualified advisor.
How is this different from the Compound Interest calculator?
The classic Compound Interest tool uses A = P(1+r/n)^(n·t) with a chosen n (monthly, daily, …). This Daily Compound page specializes in day-by-day modeling with reinvest %, deposits, weekend filters, charts, and snapshots.
Where did reinvest, deposits, and weekends go?
They live under More options so the main form stays simple: principal, rate mode, rate, and time. Open More options when you need partial reinvestment, extra deposits, or business-day compounding.
When should I exclude weekends?
Some educational trading or business-day sketches skip Saturdays and Sundays. Most bank savings products still accrue on a calendar-day basis — match the product you are modeling.
What does the Daily Compound Interest Calculator on MyCalcsWorld actually compute?
Project daily compounding with daily or annual rates, optional reinvest %, deposits, and business-day filtering — plus balance chart and snapshots. You enter Principal (money), Interest mode, Interest rate (%), Years, Months, and the result panel updates in your browser — free, no signup. Below the form you will find when-to-use tips, common mistakes, a worked example, formula notes, and FAQs for this tool.
Questions about this tool? Contact MyCalcsWorld · mycalcsworldcontact