🪵 Plank Making Calculator

How Plank Make Profit Works

The Plank Make spell on the Lunar spellbook converts one log into a plank per cast. It requires 86 Magic and costs 1 nature rune, 2 astral runes, and 15 earth runes, plus a sawmill fee that varies by log type: 70 GP for regular planks, 175 GP for oak, 350 GP for teak, and 1,050 GP for mahogany. Each cast gives 90 Magic XP.

At approximately 1,900 casts per hour, Plank Make converts logs into planks faster than running to the sawmill manually. The profit per plank equals the plank's GE price minus the log cost, rune costs, and sawmill fee. Mahogany and teak planks typically have the best margins because Construction training consumes them in large quantities, creating sustained demand.

Using a steam battlestaff eliminates water and fire rune costs, improving margins slightly. The calculator above factors in all costs with live GE prices. For related profit methods, the Blast Furnace Calculator covers another production-based money maker, and the Fletching Calculator shows alternative uses for logs.

Strategy Tips for Plank Making

Compare mahogany vs teak planks before each session. Mahogany planks are the go-to for Construction training, creating high demand, but teak planks can occasionally have better margins due to less competition. The sawmill fee difference (1,050 GP for mahogany vs 350 GP for teak) means teak is often more forgiving when margins are tight.

Use a steam battlestaff to save on water and fire rune costs. While the spell primarily uses astral, nature, and earth runes, the steam staff covers two elements at once. Pair plank making with your own Construction training for a self-sufficient loop: make planks from logs, train Construction, and sell any excess planks.

Common Mistakes to Avoid

1. Not accounting for rune costs — The spell uses nature, astral, and earth runes per cast. These costs add up at 1,900 casts per hour and can make a seemingly profitable plank type unprofitable. The calculator above includes all costs.
2. Using the wrong staff — A steam battlestaff provides infinite water and fire runes. Other staves only cover one element. Using a basic fire staff means you still pay for water runes.
3. Ignoring the sawmill as an alternative — The Woodcutting Guild sawmill is faster than the Plank Make spell if you have a surplus of coins and want to save runes. Compare both methods before committing.