About &
Methodology
How our calculators work, where our data comes from, and the limitations you should know about.
What We Do
Imagine Calculator provides free financial tools to help you visualize investment outcomes, understand the effects of compounding, and explore historical market data. Our goal is to make financial concepts accessible and tangible through interactive calculators and data-driven scenarios.
All tools on this site are for educational purposes only and do not constitute financial advice. We believe that understanding how markets have performed historically can help people make more informed decisions about their financial future.
Our Calculators
DCA Calculator
Simulate dollar-cost averaging into cryptocurrencies or stocks. See how periodic investments accumulate over time using historical price data.
Compound Interest Calculator
Project how your money grows with compound interest and optional monthly contributions. Visualize the power of compounding over any time horizon.
Crypto Profit Calculator
Calculate your profit or loss on a cryptocurrency trade. Enter your buy price, sell price, and investment amount to see your return.
Percentage Calculator
Three percentage tools in one: find a percentage of a number, determine what percent one number is of another, or calculate percentage change.
Inflation Calculator
See how much purchasing power your money has lost over time using real U.S. CPI data from the Bureau of Labor Statistics.
What-If Scenarios
Explore historical investment returns with "What If" scenario pages. See what would have happened if you invested in Bitcoin, Ethereum, the S&P 500, or other assets in past years.
Methodology
All calculations are performed client-side using deterministic, open formulas. Below are the core formulas behind each tool, explained in plain English.
Compound Interest
Compound interest is interest earned on both the initial principal and on previously accumulated interest. The longer your money compounds, the faster it grows.
A = P(1 + r/n)nt
Where P = principal, r = annual interest rate, n = compounding frequency per year, t = time in years, and A = final amount.
Compound Annual Growth Rate (CAGR)
CAGR measures the average annual growth rate of an investment over a specified period longer than one year. It smooths out volatility to show a single annualized return figure.
CAGR = (endValue / startValue)1/years − 1
This gives the hypothetical constant rate at which an investment would have grown year-over-year to reach its final value.
Dollar-Cost Averaging (DCA)
DCA involves investing a fixed amount at regular intervals regardless of price. This strategy reduces the impact of volatility by buying more units when prices are low and fewer when prices are high.
Total units = ∑ (monthly investment ÷ price at each period)
We sum each monthly purchase at the historical price for that period. For yearly data, monthly buys are spread across the year at the year-start price.
Inflation Adjustment
To express a nominal dollar value in real (inflation-adjusted) terms, we use the Consumer Price Index to account for changes in purchasing power over time.
Real value = nominal value × (CPIstart ÷ CPIend)
This deflates a current dollar amount back to what it would be worth in an earlier year's purchasing power.
Data Sources
Cryptocurrency Prices
Live cryptocurrency prices are sourced from the CoinGecko API. Prices are fetched in real time when you use our calculators. Historical crypto prices use yearly snapshots stored in our static dataset.
Consumer Price Index (CPI)
Inflation data uses CPI-U (Consumer Price Index for All Urban Consumers) annual averages published by the U.S. Bureau of Labor Statistics. Our dataset covers 2000 through 2025, with the most recent year being an estimate until official BLS figures are released.
Benchmark Data
S&P 500 index values and gold prices are sourced from publicly available historical datasets and are used as comparison benchmarks in our What-If scenario pages. These are stored as year-start snapshots.
Update Frequency
Live cryptocurrency prices update in real time via the CoinGecko API. Historical price datasets and CPI data are updated periodically as new official data becomes available. Scenario pages are regenerated at build time with the latest static data.
Limitations & Disclaimers
- Past performance does not guarantee future results. Historical returns shown on this site are not indicative of future performance. Markets are inherently unpredictable.
- Taxes, fees, and transaction costs are not included. Our calculations show gross returns only. Actual investment returns will be lower after accounting for taxes, brokerage fees, gas fees, and other costs.
- Historical prices are year-start approximations. We use year-start price snapshots rather than daily data. Actual purchase prices would have varied throughout each year.
- Cryptocurrency prices are volatile. Crypto asset values can change rapidly and significantly. Live prices displayed may differ from actual exchange prices due to data latency and market fragmentation.
- Not financial advice. Imagine Calculator is an educational tool. Nothing on this site should be construed as investment advice, a recommendation, or a solicitation to buy or sell any asset. Always consult a qualified financial advisor before making investment decisions.
Data last verified
March 2026