Treasure & History Tools & Calculators
Free, practical tools for the treasure hunter and history lover — reckon the melt value of precious metal, convert gold karats, write dates in Roman numerals, estimate a gemstone’s carats, value a coin hoard, and measure land the medieval way.
Precious Metal Melt Value Calculator
Estimate the intrinsic melt value of a gold, silver, or other precious-metal item from its weight, purity, and the spot price per gram — the raw metal worth behind coins, jewellery, and artifacts
Gold Karat Converter
Convert a gold karat rating into its purity percentage and fineness (parts per thousand) — read a 24k, 22k, 18k, or 14k mark, or a 999/916/750/585 hallmark, at a glance
Roman Numeral Converter
Turn any number from 1 to 3999 into standard subtractive Roman numerals — the notation carved on monuments, minted on coins, and inked in medieval manuscripts
Gemstone Carat Weight Calculator
Estimate the carat weight of a cut gemstone from its length, width, and depth in millimetres and a shape/density factor — a quick reckoning for a mounted stone you cannot weigh
Treasure Hoard Value Calculator
Total the value of a mixed coin hoard from the count of gold and silver coins and a value for each — a back-of-envelope reckoning for a find of medieval or ancient coinage
Medieval Land Converter
Convert acres into medieval English land units — hides (120 acres), virgates (30 acres), and roods (quarter-acres) — the assessment measures of the Domesday world