Compound Interest Calculator
Compare and convert nominal interest rates across all compounding frequencies (APR to APY, Daily to Monthly, Continuous compounding).
Compound Interest Calculator
Interest Rate Converter & Compounding Frequency Comparison Tool
The Compound Interest Calculator below can be used to compare or convert the interest rates of different compounding periods. Please use our Interest Calculator to do actual calculations on compound interest.
• Source Interest (%): Enter your nominal interest rate (e.g. 6%) and its compounding frequency (e.g. Monthly APR).
• Target Frequency: Select your desired output compounding interval (e.g. Annually APY, Daily, or Continuous).
• High Precision: Output is calculated using continuous & discrete exponential models formatted to 5 decimal places.
Interest Rate Converter
Equivalent Rates Across All Compounding Frequencies
Full cross-compounding matrix for an input of 6% (Monthly (APR))
| Compounding Frequency | Periods / Year | Equivalent Nominal Rate (%) | Effective Annual Yield (APY) |
|---|---|---|---|
| Annually (APY)Target | 1 | 6.16778% | 6.16778% |
| Semi-Annually | 2 | 6.07550% | 6.16778% |
| Quarterly | 4 | 6.03005% | 6.16778% |
| Monthly (APR)Source | 12 | 6.00000% | 6.16778% |
| Semi-Monthly | 24 | 5.99252% | 6.16778% |
| Bi-Weekly | 26 | 5.99194% | 6.16778% |
| Weekly | 52 | 5.98850% | 6.16778% |
| Daily | 365 | 5.98554% | 6.16778% |
| Continuous | ∞ | 5.98505% | 6.16778% |
What is Compound Interest & How Do Rates Convert?
Simple vs. Compound Interest
Simple interest is calculated exclusively on the principal amount invested or borrowed. Compound interest, on the other hand, is earned on both the initial principal and the accumulated interest from preceding periods (earning interest on interest).
The more frequently interest is compounded (e.g., daily vs. annually), the faster the balance expands, resulting in a higher Effective Annual Rate (EAR / APY) for the same nominal APR.
Conversion Formulas
Related Financial Calculators
Explore our complete collection of verified interest, loan, and investment tools:
Understanding Compound Interest Calculator & Formula
The Compound Interest Calculator on CalculatorScale.com is engineered to deliver instant, mathematically verified calculations conforming strictly to standard institutional equations. Whether planning long-term investments, managing household budgets, tracking clinical fitness targets, analyzing academic genetics, calculating veterinary dosages, or converting dimensional units, every calculation updates dynamically in real time without lag.
Every formula used in this tool adheres to certified international standards, including World Health Organization biometric metrics, veterinary clinical guidelines, NIST physical conversion constants, and standard biological equations. Results are computed entirely client-side inside your browser with complete data privacy, ensuring your sensitive numbers and statistics never leave your device.
Our calculators are 100% free with no registration, subscriptions, or paywalls required. You can toggle between imperial and metric units, customize input parameters, export calculation summaries, or embed this calculator directly into your own website or blog.
How to Use the Compound Interest Calculator
- 1 Enter your nominal Input Interest (%) rate (e.g., 6.0%).
- 2 Select your Source Compounding Frequency (Annually, Semi-Annually, Quarterly, Monthly, Semi-Monthly, Bi-Weekly, Weekly, Daily, or Continuous).
- 3 Select your Target Compounding Frequency to convert into.
- 4 View the instant, high-precision equivalent interest rate formatted to 5 decimal places (e.g., 6.16778%).
- 5 Review the full multi-frequency equivalent rates matrix below to compare rates across all 9 compounding frequencies simultaneously.
Compound Interest Calculator — Frequently Asked Questions
Q1 What is the difference between APR and APY / EAR? ▾
Annual Percentage Rate (APR) is the simple nominal annual rate without factoring in intra-year compounding. Annual Percentage Yield (APY), or Effective Annual Rate (EAR), accounts for the effect of compounding, representing the true annual percentage return earned or paid on a balance.
Q2 Why does more frequent compounding increase the effective rate? ▾
Because interest is added to the principal balance more frequently (e.g., daily vs annually), subsequent interest calculations are applied to progressively larger balances. This creates an exponential growth effect, making daily compounding yield a higher APY than annual compounding for the same nominal rate.
Q3 How does continuous compounding work? ▾
Continuous compounding represents the mathematical limit of infinite compounding intervals using Euler's constant (e). The effective annual rate is given by EAR = e^r - 1, and the equivalent nominal rate is given by r = ln(1 + EAR).
Q4 Where can I calculate total investment growth with dollar contributions? ▾
To simulate portfolio growth, initial lump sums, recurring monthly/annual deposits, taxes, and inflation, please visit our dedicated Interest Calculator (Wealth Growth) tool.
More in General investment calculators
Interest Calculator
EssentialThis Compound Interest Calculator can help determine the compound interest accumulation and final balances on both fixed principal amounts and additional periodic contributions. There are also optional factors available for consideration, such as the tax on interest income and inflation.
Investment Calculator
PopularForecast investment portfolio growth, starting deposits, periodic contribution requirements, or investment timeline across 4 multi-variable modes with inflation and tax adjustments.
Interest Rate Calculator
PopularThe Interest Rate Calculator determines real interest rates on loans with fixed terms and monthly payments. For example, it can calculate interest rates in situations where car dealers only provide monthly payment information and total price without including the actual rate on the car loan. To calculate the interest on investments instead, use the Interest Calculator, or use the Compound Interest Calculator to understand the difference between different interest rates.
Simple Interest Calculator
PopularCalculate simple interest, ending balances, annual percentage rates, or time periods with the classic formula I = P × r × t across days, months, and years, with periodic contribution options and compound comparisons.
CD Calculator
PopularCalculate the total accumulated compound interest and ending balance on a Certificate of Deposit (CD) over any term, accounting for multiple compounding frequencies and marginal income tax drag.
Mutual Fund Calculator
PopularEstimate mutual fund ending balance, net return, total fee drag, and annualized Net Internal Rate of Return (IRR) accounting for front-end sales loads, back-end redemption fees, and ongoing expense ratios.
Explore All 4,700+ Calculators by Category
Genetics, molecular laboratory science, veterinary dosages, animal gestation, agronomy, and forestry.
Stoichiometry, chemical solutions, thermodynamics, kinetics, electrochemistry, and organic reactions.
Concrete, roofing, brick, framing, lumber spans, driveway paving, gravel, and material specifications.
Precision metric and imperial unit converters for length, area, volume, mass, pressure, temperature, and speed.
Carbon footprint, solar energy payback, tree sequestration, recycling offsets, and sustainable living metrics.
Travel durations, clothing and shoe sizes, fuel economy, home budgeting, sleep cycles, and daily routines.
Mortgage amortization, compound interest, loans, retirement planning, taxes, investments, and salary projections.
Culinary volume-to-weight conversions, baking hydration, ingredient scaling, pizza dough, and party food planning.
BMI, daily caloric needs (TDEE/BMR), body fat percentage, pregnancy due dates, clinical dosage, and pediatric metrics.
Scientific calculators, fractions, percentages, geometry, trigonometry, algebra, linear systems, and matrices.
Kinematics, Newtonian dynamics, thermodynamics, fluid mechanics, electromagnetism, optics, and relativity.
Heart rate training zones, running pace, triathlon pacing, cycling power, calories burned, and 1RM lifting benchmarks.
Standard deviation, normal distribution (Z-scores), confidence intervals, sample size, and probability odds.
Education GPA, photography exposures, music BPM, data storage, network bandwidth, and specialty calculations.