Math Functions - SPARQLqueries

Math Function Reference

SPARQL provides various mathematical functions for numeric calculations.

Function	Description	Example
`ABS(x)`	Absolute value	`ABS(-5)` → 5
`ROUND(x)`	Round to nearest integer	`ROUND(3.7)` → 4
`CEIL(x)`	Round up to integer	`CEIL(3.2)` → 4
`FLOOR(x)`	Round down to integer	`FLOOR(3.9)` → 3
`RAND()`	Random number 0-1	`RAND()` → 0.573...
`+, -, *, /`	Basic arithmetic	`10 / 3` → 3.333...

Basic Arithmetic

Perform calculations on numeric properties.

Calculate Population Density

Divide population by area to get density:

Country Population Density

Run

SELECT ?country ?countryLabel ?population ?area ?density WHERE {
  ?country wdt:P31 wd:Q6256 .      # instance of: country
  ?country wdt:P1082 ?population .  # population
  ?country wdt:P2046 ?area .       # area in km²
  FILTER(?area > 0)                # avoid division by zero
  BIND(?population / ?area AS ?density)
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en" . }
}
ORDER BY DESC(?density)
LIMIT 50

Price Per Unit Calculation

Calculate ratios and unit prices:

Building Height to Floor Ratio

Run

SELECT ?building ?buildingLabel ?height ?floors ?heightPerFloor WHERE {
  ?building wdt:P31/wdt:P279* wd:Q11303 .  # skyscraper
  ?building wdt:P2048 ?height .        # height in meters
  ?building wdt:P1101 ?floors .        # number of floors
  FILTER(?floors > 0)
  BIND(?height / ?floors AS ?heightPerFloor)
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en" . }
}
ORDER BY DESC(?height)
LIMIT 50

Rounding Functions

Control decimal precision with ROUND, CEIL, and FLOOR.

Round to Nearest Integer

Clean up calculated values:

Rounded Population Density

Run

SELECT ?city ?cityLabel ?population ?area ?densityRounded WHERE {
  ?city wdt:P31/wdt:P279* wd:Q515 .  # city
  ?city wdt:P1082 ?population .
  ?city wdt:P2046 ?area .
  FILTER(?area > 0 && ?population > 1000000)
  BIND(ROUND(?population / ?area) AS ?densityRounded)
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en" . }
}
ORDER BY DESC(?densityRounded)
LIMIT 30

Ceiling and Floor

Round up or down:

Height Categories Using CEIL

Run

SELECT ?mountain ?mountainLabel ?elevation ?elevationKm WHERE {
  ?mountain wdt:P31 wd:Q8502 .     # mountain
  ?mountain wdt:P2044 ?elevation . # elevation in meters
  FILTER(?elevation > 7000)
  BIND(CEIL(?elevation / 1000) AS ?elevationKm)  # Round up to km
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en" . }
}
ORDER BY DESC(?elevation)
LIMIT 30

Absolute Value

Use ABS() to get magnitude regardless of sign.

Temperature Extremes

Find places with extreme temperatures (hot or cold):

Cities with Extreme Temperature Variations

Run

SELECT ?city ?cityLabel ?latitude ?absLatitude WHERE {
  ?city wdt:P31/wdt:P279* wd:Q515 .  # city
  ?city wdt:P1082 ?population .
  ?city wdt:P625 ?coord .
  BIND(geof:latitude(?coord) AS ?latitude)
  BIND(ABS(?latitude) AS ?absLatitude)
  FILTER(?population > 100000)
  FILTER(?absLatitude > 60)  # Far from equator (north or south)
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en" . }
}
ORDER BY DESC(?absLatitude)
LIMIT 30

Difference from Average

Find how far values deviate from a reference:

People Born Far from Year 1900

Run

SELECT ?person ?personLabel ?birthYear ?yearsFrom1900 WHERE {
  ?person wdt:P106 wd:Q170790 .      # mathematician
  ?person wdt:P569 ?birthDate .
  BIND(YEAR(?birthDate) AS ?birthYear)
  BIND(ABS(?birthYear - 1900) AS ?yearsFrom1900)
  FILTER(?yearsFrom1900 <= 50)  # Within 50 years of 1900
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en" . }
}
ORDER BY ?yearsFrom1900
LIMIT 50

Random Sampling

Use RAND() to get random samples of data.

Random Selection

Get a random sample of items:

10 Random Paintings

Run

SELECT ?painting ?paintingLabel ?creatorLabel WHERE {
  ?painting wdt:P31 wd:Q3305213 .  # painting
  ?painting wdt:P170 ?creator .
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en" . }
}
ORDER BY RAND()
LIMIT 10

Random with Conditions

Random sample within constraints:

5 Random French Writers

Run

SELECT ?writer ?writerLabel ?birthYear WHERE {
  ?writer wdt:P106 wd:Q36180 .      # writer
  ?writer wdt:P27 wd:Q142 .        # country: France
  ?writer wdt:P569 ?birthDate .
  BIND(YEAR(?birthDate) AS ?birthYear)
  FILTER(?birthYear >= 1800 && ?birthYear <= 1900)
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en" . }
}
ORDER BY RAND()
LIMIT 5

Percentage Calculations

Calculate percentages and proportions.

Percentage of Total

Calculate what percentage each value represents:

Country Population as % of World

Run

SELECT ?country ?countryLabel ?population ?percentOfWorld WHERE {
  BIND(8000000000 AS ?worldPop)  # Approximate world population
  ?country wdt:P31 wd:Q6256 .
  ?country wdt:P1082 ?population .
  BIND(ROUND(?population * 10000 / ?worldPop) / 100 AS ?percentOfWorld)
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en" . }
}
ORDER BY DESC(?population)
LIMIT 20

Ratio Calculations

Compare two quantities:

GDP Per Capita

Run

SELECT ?country ?countryLabel ?gdp ?population ?gdpPerCapita WHERE {
  ?country wdt:P31 wd:Q6256 .      # country
  ?country wdt:P2131 ?gdp .        # nominal GDP
  ?country wdt:P1082 ?population .
  FILTER(?population > 0)
  BIND(ROUND(?gdp / ?population) AS ?gdpPerCapita)
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en" . }
}
ORDER BY DESC(?gdpPerCapita)
LIMIT 30

Unit Conversions

Convert between different units of measurement.

Meters to Feet

Convert elevation from meters to feet:

Mountain Heights in Feet

Run

SELECT ?mountain ?mountainLabel ?elevationM ?elevationFt WHERE {
  ?mountain wdt:P31 wd:Q8502 .       # mountain
  ?mountain wdt:P2044 ?elevationM .  # elevation in meters
  FILTER(?elevationM > 8000)
  BIND(ROUND(?elevationM * 3.28084) AS ?elevationFt)
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en" . }
}
ORDER BY DESC(?elevationM)

Kilometers to Miles

Convert distance units:

River Lengths in Miles

Run

SELECT ?river ?riverLabel ?lengthKm ?lengthMi WHERE {
  ?river wdt:P31 wd:Q4022 .       # river
  ?river wdt:P2043 ?lengthKm .    # length in km
  FILTER(?lengthKm > 3000)
  BIND(ROUND(?lengthKm * 0.621371) AS ?lengthMi)
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en" . }
}
ORDER BY DESC(?lengthKm)
LIMIT 20

Conditional Calculations

Combine math with IF statements for conditional logic.

Categorizing by Size

Assign size categories based on numeric values:

City Size Categories

Run

SELECT ?city ?cityLabel ?population ?sizeCategory WHERE {
  ?city wdt:P31/wdt:P279* wd:Q515 .
  ?city wdt:P17 wd:Q30 .           # USA
  ?city wdt:P1082 ?population .
  BIND(
    IF(?population > 1000000, "Major City",
    IF(?population > 500000, "Large City",
    IF(?population > 100000, "Medium City",
    "Small City"))) AS ?sizeCategory)
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en" . }
}
ORDER BY DESC(?population)
LIMIT 50