The short version
- Every item has its own four-hour buy limit, and the timer starts when you make your first purchase of that item.
- Buying a single unit starts the clock, so a small test purchase spends the same window as a full one.
- Profit per cycle is margin multiplied by buy limit — which is why a small margin on a high-limit item often beats a large one.
- You cannot raise a buy limit. Scaling means trading more items at once, not more of one item.
Every tradeable item in Old School RuneScape has a buy limit: a cap on how many units a single account can purchase within a four-hour window. It is the mechanic that decides your ceiling on any given item, and it is why the item with the widest margin is very often not the item you should be trading.
How the timer works
The four-hour window is per item, and it starts when you make your first purchase of that item — not at a fixed time of day, and not globally across your account.
If you buy 5,000 nature runes at 14:00, your nature rune limit resets at 18:00. Buying cannonballs at 15:00 starts a separate timer for cannonballs, resetting at 19:00. The two do not interact.
Partial purchases still start the clock. Buying a single unit of an item begins that item's four-hour window, so the limit will reset four hours from that first unit regardless of whether you bought one or the full allowance.
This matters more than it sounds. A common error is buying a handful of something to test the market, then wanting to commit properly twenty minutes later and finding most of the window already spent.
Why limits exist
Without them, a player with a large enough bank could buy the entire supply of an item and set whatever price they liked. Buy limits make cornering the market impractical for anything with meaningful supply, because acquiring enough stock takes days rather than minutes.
They also protect ordinary players. If someone could instantly clear every Prayer potion on the Grand Exchange, the price would spike and everyone else would pay for it.
What limits mean for your trading
They cap your profit per item, not your profit overall
The formula is simple and it governs everything:
maximum profit per cycle = margin after tax × buy limit
An item with a 40,000 GP margin and a buy limit of 8 caps out at 320,000 GP per four hours. An item with a 25 GP margin and a limit of 30,000 caps out at 750,000 GP in the same window — more than twice as much, from a margin that looks 1,600 times worse.
This is why profit per buy limit is the right ranking rather than the headline spread. Ranking by margin alone produces a list topped by items nobody can trade in quantity.
They make diversification mandatory, not optional
Because each item has its own limit and its own timer, the way to deploy more capital is to trade more items simultaneously rather than more of one item.
With eight offer slots, a reasonable working pattern is:
- Buy your full limit on several items at once
- While those fill, place sell offers on whatever completed last cycle
- Rotate as timers reset
Your real constraint stops being GP and becomes slots and attention.
They reward planning your cycles
If you know a limit resets at 18:00, being at the Grand Exchange at 18:00 rather than 19:30 is worth an entire extra cycle over a session. Players who trade seriously keep track of their reset times, either mentally or with a tool.
Typical limits by item type
Limits are set individually per item, but the general pattern is:
- Very high (10,000+) — runes, ammunition, common raw materials. Designed for bulk consumption.
- High (1,000–13,000) — potions, food, logs, ores, bars.
- Moderate (100–1,000) — mid-tier equipment, treated seeds, some consumables.
- Low (8–70) — high-value weapons and armour, boss drops.
- Very low (1–8) — the rarest and most expensive items in the game.
Broadly, the more consumable an item is, the higher its limit. Equipment you buy once has a low limit; supplies you burn through constantly have high ones.
The exact limit for an item is worth looking up before you plan around it.
Items with no published limit
A small number of items have no buy limit at all. These are generally items with unlimited supply from shops or with no meaningful market. They appear as "no published limit" on our item pages rather than as a number.
For flipping purposes, an item without a limit is usually one without a market worth trading.
Working around limits
You cannot increase a buy limit. There is no membership perk, quest reward or achievement that raises it. What you can do:
Trade more items. The only genuine way to scale. Eight slots on eight different items with resetting timers is eight independent income streams.
Time your cycles. Being present at reset is worth real money over a session.
Buy in one action. Placing one offer for your full limit rather than several small ones avoids wasting part of the window on a test purchase.
Match capital to limit. If you have 50M and the item's full limit costs 800,000 GP, that item can absorb almost none of your bank. Our capital guides cover which items suit which bank sizes.
The practical takeaway
When you evaluate an item, look at the buy limit before the margin. Multiply them together, and compare that number against other items. That single calculation will change which trades you make more than any other habit.
The GE profit calculator does the arithmetic if you want to check a specific item, and every table on OSRS Helper shows both figures side by side so the comparison is always available.
What a full cycle actually looks like
The mechanic is simple to state and easy to mismanage. Here is a single item followed through one complete four-hour window.
- 09:00 — you buy 1 unit
Your four-hour window for this item opens the moment the first unit fills, not when you place the offer. It will now reset at 13:00 regardless of what else you do.
- 09:00 — you buy the remaining allowance
Because the clock is already running, buying the rest costs you nothing in time. This is why testing with a small purchase is expensive: it starts the timer for the whole allowance.
- 09:20 — the buy completes, you list the sell
Selling is not limited. You can sell as many as you hold, whenever you like. Only buying is capped.
- 13:00 — the window resets
A fresh allowance is available. If you are not there, the window simply passes — allowances do not accumulate.
Limits by category, roughly
Limits are set per item and Jagex adjusts them, so treat these as the shape of the system rather than a lookup table. The item page for anything you are trading shows its current limit.
| Category | Typical limit | What that implies |
|---|---|---|
| Common runes, arrows | 10,000–30,000 | Capital-hungry, tiny margins, fast cycles |
| Food, basic potions | 1,000–10,000 | Comfortable middle ground |
| Ores, bars, logs | 10,000–13,000 | Skilling supply, steady demand |
| Mid-tier armour and weapons | 70–125 | Where profit per cycle is usually highest |
| High-end weapons, rares | 8 | Large margins, small allowances, slow |
The pattern is deliberate: the cheaper and more consumable an item is, the more of it you may buy. The limit is a brake on cornering the market, and it scales with how easy an item would be to corner.
The eight-slot arithmetic
Buy limits interact with offer slots, and the interaction is what actually caps your income.
You have eight Grand Exchange slots. Each item has its own independent four-hour timer. So the ceiling on what you can earn in a four-hour block is:
maximum per block = sum of (margin x buy limit) for your eight best items
Two consequences follow, and they are the whole strategy:
- More items beats more money. Once you can afford a full limit of an item, extra capital does nothing for that item. Growth comes from finding another item worth a slot.
- Staggered timers are an advantage, not a nuisance. Because each item resets on its own clock, a portfolio bought at different times gives you something to do most times you log in, rather than one big reset you have to be present for.
Working around a limit
You cannot raise a limit, but there are three legitimate ways to need it less.
Trade more items
The real answer
Eight items each returning 60k a cycle beats one item you wish had a bigger allowance.
This is the only approach that scales.
Trade the same item over more windows
Partial
Being present at each reset earns an extra cycle per session.
Helps, but caps out at six windows a day.
The third option — a second account — is worth naming only to say that it does not help. Trading between your own accounts to bypass limits is against the rules, and the risk is your main account.
Common questions
- How long is the buy limit in OSRS?
- Four hours. The window starts when you make your first purchase of that item, not at a fixed time of day, and each item has its own independent timer.
- When does the GE buy limit reset in OSRS?
- Exactly four hours after your first purchase of that item. Buying a single unit starts the clock, so a small test purchase spends the same window as a full one.
- Can you increase your buy limit in OSRS?
- No. There is no membership perk, quest reward or achievement that raises it. The only way to trade more is to trade more items at once, since every item has its own separate limit and timer.
