How Much Olive Oil Does One Olive Tree Produce?
A single healthy, mature olive tree yields roughly 1.5 to 4 litres of olive oil in a good year — though that figure swings widely with the variety, the tree’s age, the growing conditions and, above all, how heavily it happens to be cropping that season. The rough rule of thumb the mill runs on is that it takes around 5 kilograms of olives to press one litre of oil, and a well-established tree in its prime might drop anywhere from 15 to 40 kilograms of fruit. Do the sums and you land at that 3-to-8-kilogram-per-litre, few-litres-per-tree range. It sounds modest, and it is — which is exactly why olive oil has always been treated as something precious rather than something cheap.
The maths: from fruit on the branch to oil in the bottle
Two numbers do most of the work here. The first is fruit yield per tree; the second is oil yield from that fruit — what millers call the extraction rate.
Fruit yield is the wildly variable one. A young tree just coming into bearing might give you 5 kilograms. A mature tree in a well-tended grove commonly sits in the 15 to 40 kilogram band, and a big old veteran on deep soil with plenty of water can push far beyond that in a bumper year — 100 kilograms or more is not unheard of, though it is the exception, not the rule. Traditional dryland groves crop far more lightly than intensively irrigated modern plantings.
Extraction rate is steadier but still moves around. Most table-and-oil varieties give up their oil at roughly 15 to 22% of the fruit’s weight, which is where the familiar “5 kilos of olives per litre” shorthand comes from (oil is a touch lighter than water, so a litre weighs about 0.91 kilograms). Riper olives and oilier varieties press out more; olives picked green for a peppery, robust oil give up less, but reward you with better flavour and keeping quality. It is a genuine trade-off, and every grower and miller has an opinion about where the sweet spot lies.
| Tree stage / type | Typical fruit per tree | Approx. oil (at ~5 kg/L) |
|---|---|---|
| Young tree, first bearing (4–7 yrs) | 3–8 kg | ~0.5–1.5 L |
| Mature tree, traditional dryland grove | 15–25 kg | ~3–5 L |
| Mature tree, well-fed / irrigated | 25–40 kg | ~5–8 L |
| Old veteran tree, bumper “on” year | 50–100+ kg | ~10–20+ L |
Treat these as honest ballparks rather than promises. The single biggest reason your own tree won’t match the table in any given year is the olive’s most famous habit, which deserves its own heading.
Why one tree’s yield changes so much year to year
Olive trees are alternate bearing, or biennial. A heavy “on” year, when the branches are groaning, is usually followed by a light “off” year while the tree recovers. This is completely normal and largely built into the plant — the fruit-laden season drains the tree’s reserves, so it takes a breather the next. Growers smooth it out with careful pruning and thinning, but even the best-managed grove shows the rhythm. It is why any single-year figure for “oil per tree” can be misleading, and why growers judge a tree over several seasons, not one.
A handful of other factors move the needle:
- Variety. Some cultivars are naturally oilier and heavier-cropping than others. A name like Koroneiki, Arbequina or Frantoio tells you about the variety’s character, not simply where it grows — plenty of well-known varieties are now planted far from their original homelands, so a variety’s name should never be read as a country of origin. For more on this, see our olive varieties encyclopedia.
- Age. Trees take a few years to bear at all and roughly 8–12 years to hit full stride. The good news: olives are extraordinarily long-lived, and a tree can keep producing for centuries.
- Water and soil. Irrigated trees on good ground simply grow more fruit. Traditional dryland groves crop less but often give more concentrated, characterful oil.
- Weather at flowering. A hot, dry spell or heavy rain when the tree is in blossom can knock out a big share of the potential crop in a matter of days.
- Pruning, feeding and pest pressure. A neglected tree hides its fruit in a tangle of shade; the olive fruit fly and other pests can spoil a crop before it ever reaches the mill.
There is also the matter of when you pick. Harvest early for green, robust oil and you accept a lower yield in exchange for punchier flavour and more antioxidants. Wait for the fruit to ripen fully and you’ll squeeze out more litres, but the oil is milder and won’t keep as long. Neither is “correct” — it is a choice about the oil you want. If you’re pressing your own, our guide to harvesting and pressing olives walks through the timing.
So the short version: one tree, one litre or one gallon? Reasonable answers, all true depending on the year. Plant a small row of six or eight healthy trees and, averaged across the good years and the lean ones, you can realistically look to keeping a household in fresh oil most seasons — which is precisely how Mediterranean families have done it for generations.
How much olive oil from one tree — common questions
How many olives does it take to make one litre of olive oil?
Roughly 5 kilograms of olives, give or take, for one litre. Oilier varieties and riper fruit need a little less; green-picked olives need more. As a rough count that’s somewhere in the region of a thousand-odd olives per litre, though olive size varies enormously.
How long before a new olive tree produces oil?
Expect a small crop from around 4 to 7 years old, with the tree reaching full, dependable production at roughly 8 to 12 years. They’re slow to start but famously long-lived, so patience pays off for decades.
Why did my olive tree produce loads one year and almost nothing the next?
That’s alternate (biennial) bearing — a natural heavy “on” year followed by a lighter “off” year while the tree recovers its reserves. Good pruning and thinning soften the swing, but you’ll rarely eliminate it entirely.
Can a single tree supply a family’s olive oil?
In a strong year a mature tree can give several litres, which goes a fair way. But because of off years, most families plant a small handful of trees so the good and lean seasons average out to a steady supply.