Blast Furnace

About the Blast Furnace calculator

Ironman-honest Blast Furnace numbers: buy ore from Ordan, smelt it, and see real XP per hour, gp per hour, and gp per XP for every bar, plus a full plan (ores to buy, total cost, hours) to reach a target Smithing level. Most published Blast Furnace rates assume a main buying ore off the Grand Exchange; this models the loop an ironman actually runs.

How the rates are computed

The hour is split between two jobs: buying the ore from Ordan and smelting it. Buying runs at 7,776 ore per hour, the rate the wiki publishes for its own buy-and-bank money maker (288 inventories of 27 ore), measured with stamina potions. Smelting runs at the wiki's published bars per hour for the chosen bar.

The one load-bearing assumption is the ironman penalty, which is what turns those stamina-assisted rates into ironman ones. A single percentage (default 20%, adjustable from 0 to 50%) scales both. Twenty percent is what the run energy formulas predict for a loaded 27 ore trip without staminas: you carry 61 kg, energy drains faster than it regenerates, and you end up running only a third to a half of the way. Gold drops from about 3,418 bars per hour at 0% to 2,734 at the default 20%.

Because it is a split rather than a single loop, the model works whether you buy and smelt in one trip or spend a session banking ore and smelt it all later. The totals come out the same either way.

Costs include the ore itself, the Blast Furnace coffer fee of 72,000 gp per hour, and, below Smithing 60, the foreman's fee of 2,500 gp per 10 minutes, halved if you charm him with a Ring of charos. Goldsmith gauntlets raise gold XP from 22.5 to 56.2 per bar, and the coal bag matters for coal-hungry bars (steel needs one coal per bar, mithril two) while doing nothing for iron or gold.

The coffer is charged for the smelting hours only. It drains just while you are in the basement on an official Blast Furnace world, and ore buying is spent hopping the world list for fresh stock, so those hours cost nothing and the balance can be withdrawn in the meantime. This matters most for the cheap bars: on iron the coffer used to be about half the quoted cost.

Plan mode picks a bar and a target level, then produces the exact ore shopping list, the projected hours, and the total gp, counting the foreman fee only for the stretch of the journey below level 60.

Frequently asked questions