Plank Calculator OSRS

Instantly Calculate Plank Costs, Profit & Materials. Compare Sawmill, Plank Make spell, and Grand Exchange purchase methods side-by-side. Find the cheapest conversion method for Regular, Oak, Teak, and Mahogany planks before spending your GP. or use the main construction calculator OSRS to plan your full 1-99 journey.

Using the Sawmill

The Sawmill Operator near Varrock converts logs into planks for a fixed fee. Regular planks cost 100 GP, Oak 250 GP, Teak 500 GP, and Mahogany 1,500 GP per conversion. No magic level or runes required — just bring your logs and coins.

Using the Plank Make Spell

Plank Make is a Lunar spell requiring level 86 Magic. It converts one log into a plank per cast, using runes worth approximately 70–1,050 GP depending on plank type. It also grants 90 Magic XP per cast, making it useful for training both Construction and Magic.

Buying Planks Directly

Purchasing planks directly from the Grand Exchange is the fastest option. You skip all conversion steps but pay the full market price. This method is ideal when you need planks immediately and don't have logs stockpiled.

When Each Option Is Worth Using

Use the Sawmill when you already have logs and want reliable, low-effort conversion. Choose Plank Make when you want Magic XP alongside cheaper planks. Buy from the GE when convenience matters most and the price difference is small.

Regular Planks

Only useful for levels 1–19. Very cheap to make but offer the lowest XP per plank. Switch to Oak as soon as possible.

Oak Planks

The most popular plank type for budget training. Used in Oak Larders (33+) and Oak Dungeon Doors (74+). Excellent GP/XP ratio makes them the go-to choice for most players.

Teak Planks

A mid-tier option used for Teak Garden Benches and Mounted Mythical Capes. Good balance of XP and cost. Popular with Ironmen who chop teaks on Fossil Island.

Mahogany Planks

The fastest XP per plank but the most expensive. Used for Mahogany Tables and Gnome Benches. Essential for speed-runners aiming for 99 Construction in under 15 hours.

Calculate Log Costs

The calculator multiplies your number of logs by the current Grand Exchange log price. This is your base material cost before any conversion fees.

Apply Sawmill Fees or Spell Costs

For Sawmill conversion, fixed fees (100–1,500 GP) are added per plank. For Plank Make, rune costs are calculated per cast. GE purchases use the full plank market price.

Estimate Total Conversion Cost

Total cost = (Log Price + Conversion Fee) × Number of Logs. This gives you the complete price of producing your planks.

Calculate Profit or Loss

Profit = (Plank Sell Price × Quantity) − Total Conversion Cost. A positive number means you can profit from making and selling planks.

Estimate Construction Value

Each plank type gives different Construction XP when used in furniture. The calculator estimates total XP potential based on average XP per plank.

Fastest Construction XP

Mahogany planks in Mahogany Tables or Gnome Benches give the highest XP rates at 900K–950K XP/hour. Use whichever conversion method is cheapest at the time.

Lowest GP Cost

Oak planks via Sawmill conversion offer the lowest GP per XP. Combine with Mahogany Homes contracts for even better savings.

Best GP per XP

Oak Dungeon Doors at ~5.9 GP/XP strike the best balance between speed and cost efficiency.

Ironman Resource Efficiency

Ironmen should chop teak logs on Fossil Island and use Plank Make spell for dual Magic + Construction progress.

Mahogany Homes Preparation

Mahogany Homes contracts require specific plank types per tier. Use this calculator to pre-purchase the exact planks needed for your contract tier.

How Planks Affect XP Rates

Higher-tier planks generally give more XP per build but cost significantly more. Oak Larders (8 planks, 480 XP) versus Mahogany Tables (6 planks, 840 XP) shows that more expensive planks can actually use fewer planks per build while giving more XP.

Why Furniture Choice Matters

The furniture you build determines how many planks per action and how much XP per action. Choosing the right furniture maximizes your planks' value.

Matching Planks to Your Budget

With under 50M GP, stick to Oak planks. With 50-100M GP, consider Teak methods. Over 100M GP? Mahogany planks for maximum speed.

Planning for Level Goals

Calculate total planks needed before buying. Use this calculator to compare methods and buy exactly what you need — no waste.

Mahogany Homes uses fewer planks per XP gained, dramatically reducing your total plank requirements. Traditional POH training is faster per hour but burns through significantly more planks (and GP). Most budget-conscious players find that Mahogany Homes saves 40–60% compared to traditional methods.

Watch Grand Exchange Prices

Plank and log prices fluctuate daily. Check before buying — sometimes planks are cheaper than making them yourself.

Buy Logs During Price Dips

Log prices tend to drop during off-peak hours. Monitor trends and buy in bulk when prices are low.

Compare Spell Costs Before Casting

Rune prices change. Always recalculate Plank Make costs before committing to a large batch.

Plan Planks Before Buying Materials

Use this calculator to determine exactly how many planks you need. Over-buying wastes GP.

Calculate GP per XP Instead of Total Cost

A method that looks expensive in total might actually be cheaper per XP gained.

• Comparing only plank prices without considering conversion fees
• Ignoring sawmill conversion fees when calculating total cost
• Forgetting rune costs when using Plank Make spell
• Buying unnecessary plank quantities without calculating exact needs
• Not checking GP per XP — the most important efficiency metric
• Using outdated Grand Exchange prices for cost estimates