Blast Furnace Calculator

Which bar to make at the Blast Furnace, and what it costs to your goal.

Your Smithing goal

Current Smithing level Target Smithing level

Example plan: a level 70 player going to 99

Make gold bars with goldsmith gauntlets.

315K–371K XP an hour.

Fastest XP your level allows.

Put on the belt

218,805 gold ore

No coal
Take from the dispenser

218,805 gold bars

33–39 h at 5,600–6,600 bars an hour (OSRS Wiki)
Pay the coffer

2.4M–2.8M gp

72,000 gp an hour, every level

Buy and sell for this goalGold · 70 to 99

218,805 Gold ore loading price
299–352 Stamina potion(4) loading price

Sell 218,805 gold bars loading price

ReturnLoading GE prices…

What you want

What you bring

Stamina doses an hour

36 is the OSRS Wiki's figure (9 Stamina potion(4) an hour). Ice gloves are assumed.

Every bar at the Blast Furnace

For level 70 to 99, with your settings. Tap a bar to plan with it. Ranges run from the Wiki's slower to faster pace.

What this plan does not count

Your own speed. Bars an hour are the OSRS Wiki's estimate range with ice gloves and stamina potions, not a promise.
One bar for the whole goal. The plan does not switch bars as your level rises.
Hybrid gold runs, the Smithing cape, and bronze, iron, silver, lead and cupronickel bars are not in this planner.
Ore from Ordan's shop: all ore is priced on the GE. GE buy limits (runite and adamantite ore 4,500 per 4 hours) can slow a big goal.
Price movement while you buy and sell. Prices are each item's last GE trade; a side older than 48 hours is not used.

How this is worked out

Bars = XP to your goal ÷ XP a bar, rounded up. Ore = bars. Coal = bars × the Blast Furnace's half coal (steel 1, mithril 2, adamantite 3, runite 4).
Hours = bars ÷ the Wiki's bars an hour. The Wiki works it out from trip lengths and gives a range; the lower end is 85% of the upper.
Coffer = 12 gp a tick (72,000 an hour) for every hour. Foreman = 2,500 gp per started 10 minutes while you are below 60 (15,000 an hour); a Ring of Charos(a) halves that fee and nothing else.
Return = bars × (bar sell price − 2% GE tax − ore and coal buy prices) − coffer − foreman − stamina potions. Ore, coal and potions use the instant-buy price; bars use the instant-sell price.
Sources: OSRS Wiki "Blast Furnace" (revision 15364896), "Blast Furnace/Strategies" (15364498), "Blast Furnace Foreman" (15315244) and "Ring of Charos" (15375237).

More Smithing: the Smithing calculator covers every method, and the Smithing guide explains the routes.

About the Blast Furnace

The Blast Furnace is a members' Smithing minigame under Keldagrim. You put ore and coal on the conveyor belt and take bars from the dispenser. It needs only half the coal of a normal furnace, which is why it is the main way to smelt steel, mithril, adamantite and runite bars. On the Blast Furnace worlds the dwarves run the machinery for you in return for 72,000 gp an hour from the coffer, and below level 60 Smithing the foreman charges a further 2,500 gp every 10 minutes. This calculator shows the bars, ore, coal and hours for your goal and what is left once those costs and your stamina potions are paid.

Blast Furnace FAQ

How much does the Blast Furnace cost per hour?

The coffer charges 12 gp a tick, which is 72,000 gp an hour, at every level. Below level 60 Smithing the foreman also charges 2,500 gp every 10 minutes (15,000 gp an hour). A Ring of Charos(a) halves only the foreman fee, to 1,250 gp; the coffer stays 72,000 gp an hour. Stamina potions are extra: the OSRS Wiki assumes 36 doses an hour.

Which bar gives the fastest Smithing XP at the Blast Furnace?

Gold bars with goldsmith gauntlets: 56.2 XP each at about 5,600–6,600 bars an hour, so roughly 314,720–370,920 XP an hour (OSRS Wiki estimate range, ice gloves and stamina potions). Gold bars usually sell for less than the ore, so this route costs money.

Which Blast Furnace bar makes the most profit?

It depends on current ore, coal and bar prices, so no bar is fixed here. Choose "Most profit" in the calculator: it ranks every bar your level allows at the latest GE prices, after the 2% GE tax, the coffer, the foreman and stamina potions, and shows how old each price is. If a price is missing or old, it does not rank.

How much coal does each bar need at the Blast Furnace?

Half of a normal furnace: steel bars 1, mithril bars 2, adamantite bars 3, runite bars 4 coal per bar. Gold bars need none.

Is a coal bag worth it at the Blast Furnace?

For coal bars, yes. Runite goes from about 1,150–1,350 bars an hour without one to 1,900–2,250 with one (OSRS Wiki estimate). The coal bag costs 100 golden nuggets from Prospector Percy at the Motherlode Mine. Gold bars need no coal, so the bag changes nothing for them.