Countworthy

Investing Calculators

Five free calculators for the questions long-term investors actually ask — compounding, averaging, retiring, and what a dividend really pays. Every formula is stated and sourced, and everything runs in your browser.

DRIP Calculator

Projects what reinvesting dividends does to a position year by year — dividend growth, price growth, fee drag, and a with/without-reinvestment chart. It also has a “Distribution tracks price” setting that holds the yield constant, an assumption for a fund whose distribution follows its price, and an implied-total-return line that shows the annual return your inputs add up to, so you can check them before you trust the projection.

Stock Average Calculator

Enter every lot you bought — shares and price each time — to get your weighted average cost per share and your live profit or loss at today's price. Then work it backwards: exactly how many more shares it would take to pull your average down to a target.

DCA Calculator

Projects a weekly or monthly investing plan for stocks or crypto — contributions in, expected final value out. It also shows a comparison figure: what the same money would have done invested all at once on day one, at the same return.

FIRE Calculator

Finds your FIRE number (yearly retirement spending divided by a withdrawal rate you choose), the age your projected portfolio reaches it, and your savings rate from a year-by-year projection of your actual portfolio, in today's dollars. Lean, Coast and Fat FIRE variants are computed alongside, so you see the whole range rather than one magic number.

Dividend Yield Calculator

Three modes in one: a stock's yield from price and payout, the income a given investment would produce, and your personal yield on cost. The write-up explains how a falling price lifts a yield as much as a rising dividend does, and what the payout ratio shows that a yield cannot.

Which tool do I need?

Want to know what reinvesting dividends does over 10 or 20 years? That's the DRIP Calculator. It runs your position forward with dividends reinvested and shows the same position without reinvestment next to it, so the compounding gap is visible instead of implied. For a covered-call or other high-distribution fund, its “Distribution tracks price” setting keeps the payout a constant percentage of the price. That is an assumption you choose, not how every such fund behaves.

Averaging into a position — or into a falling one? The Stock Average Calculator gives you your real weighted average across every buy, and answers the question people usually have next: how many shares at today's price would move that average to a specific target.

Comparing steady monthly buying against investing a windfall at once? The DCA Calculator models the recurring plan and puts the day-one lump sum beside it. That comparison describes a choice only for money you already have; for income invested as it arrives there is no day-one sum.

Asking how large a portfolio your spending implies, and when a projection reaches it? The FIRE Calculator turns your spending, saving and portfolio into a FIRE number and the year a constant-return projection reaches it, with Lean, Coast and Fat variants so you can see how much the target moves when the assumptions do. It does not test whether the money would last.

Just need to know what a dividend actually pays? The Dividend Yield Calculator works the yield equation all three ways round — yield from price, income from an investment, and yield on your original cost.

A note on how these model the future: each shows the assumptions behind its projection. The DRIP tool reports the total return your inputs imply, so you can compare it with a fund's published return; with “Distribution tracks price” on, dividend growth is locked to price growth, so a high yield and a higher dividend growth rate are not compounded together. That lock is the calculator's assumption, not a rule every fund follows. A projection is only worth what its assumptions are, and these tools show you the assumptions.