Oak planks give the cheapest Construction experience through standard builds, mahogany gives the fastest, and teak sits between the two. The plank tier you choose sets your entire budget, because every ordinary build of a given plank type returns exactly the same experience per plank.
Prices in this article were checked on 25 August 2026 and will move. Experience per plank is a fixed mechanic and will not.
The three tiers compared
| Oak plank | Teak plank | Mahogany plank | |
|---|---|---|---|
| Insta-buy price | 414 gp | 769 gp | 1,826 gp |
| Log price | 42 gp | 124 gp | 161 gp |
| Sawmill fee | 250 gp | 500 gp | 1,500 gp |
| Sawmill total | 292 gp | 624 gp | 1,661 gp |
| XP per plank (ordinary furniture) | 60 | 90 | 140 |
| Cost per XP (buying planks) | 6.9 gp | 8.5 gp | 13.0 gp |
| Main training use | Larders, doors | Garden benches | Tables, gnome benches |
| Best for | Lowest cost | Middle ground | Fastest training |
Experience per plank is the number that matters
A plank’s price tells you nothing on its own. What decides cost is how much experience the plank returns, and that is fixed by tier:
- Oak: 60 experience per plank. An oak chair gives 120 for 2 planks. An oak dining table gives 240 for 4. An oak larder gives 480 for 8. An oak door gives 600 for 10. Every one of them is 60 per plank.
- Teak: 90 experience per plank. A teak table gives 360 for 4. A teak garden bench gives 540 for 6.
- Mahogany: 140 experience per plank. A mahogany table gives 840 for 6. A gnome bench gives 840 for 6.
Divide the plank price by that number and you have the cost per experience. Mahogany is 4.4 times the price of oak but returns only 2.3 times the experience, which is why it works out roughly twice as expensive per experience.
The exception worth knowing
Teak has one build that breaks its own ratio. A mounted mythical cape, built in the guild trophy space of the quest hall, requires 47 Construction and completion of Dragon Slayer II. It returns 123 experience per teak plank rather than the usual 90.
That is a 37 per cent improvement on teak’s normal ratio, and it brings teak’s cost per experience below oak’s at the prices above. It is the reason mounted mythical capes are commonly cited as cheap training for accounts that have Dragon Slayer II done.
Buying planks versus the sawmill
Every plank tier can be bought finished on the Grand Exchange, or made by buying logs and paying the sawmill operator to convert them.
| Plank | Buy finished | Logs + sawmill | Cheaper on 25 Aug 2026 |
|---|---|---|---|
| Plank | 148 gp | 124 gp | Sawmill |
| Oak plank | 414 gp | 292 gp | Sawmill |
| Teak plank | 769 gp | 624 gp | Sawmill |
| Mahogany plank | 1,826 gp | 1,661 gp | Sawmill |
The sawmill was cheaper across all four tiers on the date checked, but the margins vary from comfortable on oak to narrow on mahogany. Those gaps move as log supply and plank demand shift independently, and the ranking can invert.
Sawmill conversion also costs time: buying logs, travelling, converting in batches, then banking. The cook, butler and demon butler can be sent to the sawmill on your behalf, which is one reason to reach Construction level 30 before a long grind, see the servant comparison.
There is a third route. The Plank Make spell converts a log at 70 per cent of the sawmill fee, but adds a rune cost per cast. Whether that wins depends on rune prices; the Plank Make versus buying comparison works it through.
Cost over a real goal
Ratios only matter once multiplied by the experience you need. Level 77 to 99 is 11,558,850 experience.
| Plank route for 77-99 | Planks needed | Cost on 25 Aug 2026 |
|---|---|---|
| Mahogany (gnome benches) | 82,566 | ~150.8m gp |
| Teak (garden benches) | 128,436 | ~98.8m gp |
| Oak (oak doors) | 192,650 | ~79.8m gp |
Oak needs more than twice as many planks as mahogany and still costs roughly half as much. The trade is time: more planks means more builds, more deliveries and more hours.
The cheapest plank is not always the cheapest level
Three things complicate the simple ranking.
Method availability. Oak’s cheapest late-game sink is the oak door at level 74. Below that, oak larders at 33 are the best oak build. If you are level 60 and want oak, your options are limited.
Build rate. An oak door consumes 10 planks for 600 experience. A gnome bench consumes 6 for 840. The oak route means roughly three times as many builds for the same experience, and each build is a click.
Your own time. If a Construction goal is competing with everything else you want to play, the cheap route can cost more in practice than the expensive one.
Which tier should you use
Use oak if gold is your constraint and you have the patience. Oak larders from 33, oak doors from 74.
Use teak if you want a middle path, or if you have Dragon Slayer II and can build mounted mythical capes from 47. Teak garden benches from 66 are the standard teak method.
Use mahogany if hours matter more than gold. Mahogany tables from 52, gnome benches from 77.
None of these is right in the abstract. Compare the GP cost of your Construction method with your own current level, your target and today’s plank prices, and the two columns will settle it.
Sources for this plank price guide
Experience per plank comes from the OSRS Wiki creation menus and item pages and is a fixed mechanic. Sawmill fees are fixed values from the sawmill operator. Prices are Grand Exchange insta-buy figures checked on 25 August 2026, see the GE price tracker for current values, and the GP per XP ranking for the full method-by-method comparison.