Esperanto treats physical measurements as relations between a value, a unit, and what is measured. Unit names such as metro, kilogramo, and litro are ordinary count nouns; a bare measurement used adverbially often takes accusative -n, while da connects a quantity unit to an indefinite substance or material.
Units are ordinary count nouns
After a cardinal greater than one, a spelled-out unit is plural. If the whole measurement functions as a measured complement, the unit also takes -n:
La tablo estas du metrojn longa kaj naŭdek centimetrojn larĝa.
The table is two meters long and ninety centimeters wide.
Mia valizo pezas dek ok kilogramojn.
My suitcase weighs eighteen kilograms.
The cardinals du, naŭdek, and dek ok remain invariant. The unit nouns metrojn, centimetrojn, and kilogramojn carry plural and accusative marking. This is the same measured -n used with duration and price; it is not evidence that the table or suitcase is “acting on” the units.
With exactly one unit, use singular but retain measured -n where required:
La breto estas unu metron longa.
The shelf is one meter long.
Dimensions with adjectives and verbs
A measurement can modify a dimension adjective:
La puto estas pli ol tridek metrojn profunda.
The well is more than thirty meters deep.
La nova ponto estas kvin metrojn pli larĝa ol la malnova.
The new bridge is five meters wider than the old one.
In the second example, kvin metrojn measures the difference between two widths. Pli larĝa supplies the comparison; the measurement tells how much wider.
Dimension roots can also be used as verbs. The measurement remains a complement:
La tunelo longas preskaŭ tri kilometrojn.
The tunnel is almost three kilometers long.
La skatolo altas dudek centimetrojn, sed ĝi ne estas sufiĉe larĝa.
The box is twenty centimeters high, but it is not wide enough.
These verbs are concise and neutral. In a formal specification, noun phrases such as la longo de la tunelo and la alto de la skatolo can make the measured property explicit.
Measurement attached to a noun
When a measurement describes a measurement noun such as longo, pezo, or volumeno, use de:
La kablo havas longon de dudek kvin metroj.
The cable has a length of twenty-five meters.
La pakaĵo havas pezon de 2,4 kilogramoj.
The package has a weight of 2.4 kilograms.
Here de dudek kvin metroj describes the noun longo; it is not a bare adverbial extent and therefore has no measured -n. Compare:
La kablo longas dudek kvin metrojn.
The cable is twenty-five meters long.
La longo de la kablo estas dudek kvin metroj.
The length of the cable is twenty-five meters.
In the final sentence, dudek kvin metroj is a predicate complement identifying the length, so it stays nominative. The underlying quantity is the same; syntax determines the marking.
Travel distance and distance from a reference point
A route or movement extent commonly takes measured -n:
Ni marŝis dek du kilometrojn laŭ la rivero.
We walked twelve kilometers along the river.
A distance can also specify a location relative to an overt reference point:
La haltejo estas tricent metrojn de la hotelo.
The stop is three hundred meters from the hotel.
The de la hotelo phrase names the reference point; tricent metrojn measures the separation. If no reference point is named and the distance itself locates something, standard Esperanto uses je:
Je tricent metroj staras malgranda benzinstacio.
Three hundred meters away there is a small gas station.
After je, do not add -n. Another clear pattern is tricent metrojn for, with the implicit or explicit origin supplied by context: La stacio estas tricent metrojn for de ĉi tie.
This distinction is covered more fully under distance and extent.
Weight: pezi, peza, and pezo de
Esperanto offers three regular frames:
| Frame | Example | Role of the measurement |
|---|---|---|
| pezi + -n | La valizo pezas 18 kilogramojn. | measured complement |
| esti + -n + peza | La valizo estas 18 kilogramojn peza. | degree of the adjective |
| pezo de | pezo de 18 kilogramoj | description of a noun |
The verb pezi is normally intransitive in this measurement frame. La valizo pezas dudek kilogramojn does not make kilograms an affected object; the accusative expresses measure.
Ĉu la pakaĵo pezas malpli ol kvin kilogramojn?
Does the package weigh less than five kilograms?
Volume and quantity with da
Use a unit plus da to measure an indefinite substance:
Aldonu du litrojn da akvo kaj duonan kilogramon da faruno.
Add two liters of water and half a kilogram of flour.
The direct objects are the quantities du litrojn and duonan kilogramon. Akvo and faruno follow da, so they do not take accusative -n.
Containers can function as practical quantity expressions:
Ni mendis kruĉon da akvo kaj du botelojn da suko.
We ordered a pitcher of water and two bottles of juice.
Botelo da suko presents the bottle as a quantity of juice. Botelo de vino can instead classify the bottle by association, origin, or intended content; botelo el vitro names its material. In ordinary purchasing, botelo da vino is the clearest way to say a bottleful of wine.
If the following material is definite, da is not used. Say du litroj de/el la akvo en la tanko for two liters from that identified water. The conditions for this choice are developed on the preposition da page.
Fractions, decimals, and symbols
A fraction can modify a unit like an adjective:
Restas nur duona litro da lakto en la fridujo.
Only half a liter of milk remains in the refrigerator.
For a mixed quantity, transparent coordination is easy to understand: unu litro kaj duono, du kilogramoj kaj kvarono. Decimal notation is usually shorter in measurements: 1,5 litroj, read unu komo kvin litroj.
Esperanto uses a decimal comma. In technical notation, international unit symbols are invariable and separated from the number by a space: 2,4 kg, 750 mL, 12 km. Do not add Esperanto endings to a symbol. In ordinary prose or speech, write or pronounce the unit as an Esperanto noun and apply the necessary endings.
La recepto postulas 0,75 litrojn da buljono.
The recipe calls for 0.75 liters of stock.
The spelled reading is nul komo sep kvin litrojn da buljono: digits after the decimal comma are read separately. See decimals, percentages, and mathematical reading.
A practical exchange
— Ĉu ĉi tiu skatolo taŭgas por la sendo? — Jes. Ĝi pezas nur tri kilogramojn kaj havas volumenon de dudek litroj.
— Is this box suitable for shipping? — Yes. It weighs only three kilograms and has a volume of twenty liters.
The weight is a bare measured complement (tri kilogramojn); the volume is expressed through the noun volumeno and therefore uses de dudek litroj.
Common Mistakes
Leaving a measured complement nominative
❌ La valizo pezas dek kilogramoj.
Incorrect — the bare weight complement takes accusative -n.
✅ La valizo pezas dek kilogramojn.
The suitcase weighs ten kilograms.
Adding -n after je
❌ Je ducent metrojn staras apoteko.
Incorrect — je already marks the phrase's role.
✅ Je ducent metroj staras apoteko.
Two hundred meters away there is a pharmacy.
Leaving a unit singular after a larger number
❌ La vojo longas kvin kilometron.
Incorrect — the unit noun is plural after five.
✅ La vojo longas kvin kilometrojn.
The road is five kilometers long.
Using de for an indefinite measured substance
❌ Mi aĉetis tri kilogramojn de pomoj.
Incorrect for an indefinite quantity of apples.
✅ Mi aĉetis tri kilogramojn da pomoj.
I bought three kilograms of apples.
Copying the English decimal point
❌ La botelo enhavas 1.5 litrojn.
Nonstandard Esperanto number formatting — use a decimal comma.
✅ La botelo enhavas 1,5 litrojn.
The bottle contains 1.5 liters.
Key Takeaways
Treat written-out units as ordinary nouns. Use measured -n with bare extents and with verbs such as pezi and longi; use de after nouns such as longo and pezo, and je when an unanchored distance locates something. Connect a quantity to an indefinite substance with da, preserve plural and case on unit nouns, and use a decimal comma with invariable international symbols in technical notation.
Related Topics
- Distance and ExtentA2 — Use measure -n for distances traveled, physical dimensions, differences in extent, and offsets from a reference point.
- Measures and PriceA2 — Mark bare measures of weight, size, value, and price with -n while distinguishing them from objects and prepositional phrases.
- Cardinal NumbersA1 — Use Esperanto cardinal numbers to count, quantify noun phrases, identify items, and read basic dates, times, measurements, and decimal notation.
- Decimals, Percentages, and Mathematical ReadingB2 — Read and write decimal commas, percentages, signed numbers, and common arithmetic expressions clearly in Esperanto.
- DaA2 — Use da to connect a quantity or measure to the indefinite substance, people, or things that make up that quantity.
- JeB1 — Use je for conventional clock-time, measure, body-part, and abstract relations when no more specific preposition expresses the intended role.