Gem Investment Return Calculator

Appreciation compounds over the full holding period, so even a small difference in the assumed annual rate multiplies into a large gap in Future Value and Net Profit by year ten. Buyer's premium and seller's fee are one-time percentage hits, and insurance is a flat annual cost -- none of them compound the way appreciation does.

It's the annual appreciation rate at which Sale Proceeds exactly equal total acquisition and holding costs -- the rate below which you'd lose money on the deal even before accounting for opportunity cost. Comparing your realistic appreciation expectations against this figure is a faster sanity check than working through Net Profit for every rate you might consider.

Yes -- a 15% buyer's premium means you're paying 15% more than the hammer price before the gem has appreciated at all, and a 10% seller's fee reduces whatever the gem sells for. Together those two one-time costs alone typically require several years of appreciation just to offset, which is why Break-Even Rate is rarely zero.

No. It calculates pre-tax Net Profit and ROI only. In the United States and several other jurisdictions, gains on collectibles like gemstones are frequently taxed at a higher rate than standard long-term capital gains, so your actual after-tax return will typically be lower than the figures shown here.