Some companies raise their dividends like clockwork -- the Dividend Aristocrats have done it for 25 straight years. If you believe a company's payout will grow at a steady rate forever, the Gordon Growth Model collapses all of those future dividends into one present value with startling simplicity: next year's dividend divided by your required return minus the growth rate. A $2 dividend growing 5 percent, discounted at 10 percent, is worth $42 today.

This calculator runs that valuation end to end. Enter the current annual dividend, the growth rate you expect, and the return you require for the risk -- the defaults produce next year's $2.10 dividend and a $42 intrinsic price. It also reports the dividend yield at that fair price and a price-to-dividend ratio, so you can compare the valuation against the market's current quote. Trading below $42 suggests undervaluation; above it, overvaluation -- under the model's assumptions.

The model's honesty is also its warning label. "Forever" is doing enormous work: no company grows dividends eternally, and the formula explodes if growth ever meets or exceeds your required return. Use it for mature, stable dividend payers -- utilities, consumer staples -- where constant growth is a defensible fiction, and switch to the two-stage model for anything still in a high-growth phase.

With the pre-filled defaults — Current Annual Dividend (D0) $2, Dividend Growth Rate 5%, Required Rate of Return 10% — the Constant Growth Stock Calculator returns Next Dividend (D1) $2.1000, Intrinsic Stock Price $42.00, Dividend Yield 5.00%, Price/Dividend Ratio 21.00. Change any input and those results update instantly, so you can see exactly how each number you enter moves the answer.