RI

Abbreviation with 3 meanings

RI
Stands for	Rhode Island
Meanings	3
Categories	Geography & Places, Medical, Technology & Computing

RI has three meanings. The most common are Rhode Island (US state) and Reference interval (laboratory test); it can also stand for Reserved instance.

Meanings of RI at a glance

#	RI stands for	Context
1	Rhode Island	Geography & Places › US State
2	Reference interval	Medical › Laboratory Test
3	Reserved instance	Technology & Computing › Cloud Computing

1. Rhode Island

Geography & Places · US State Abbreviations

The smallest state by area and the last of the 13 original colonies to ratify the Constitution, on May 29, 1790. Providence is the capital, and in 2020 voters approved dropping and Providence Plantations from the official state name.

Example: The sailing regatta in Newport, RI drew yachts from across New England.

Rhode Island shortens to R.I. in AP and traditional style. RI was set in 1963. Despite the name, most of the state is on the mainland; Aquidneck Island, historically called Rhode Island, holds Newport. The Ocean State nickname reflects roughly 400 miles of tidal shoreline.

2. Reference interval

Medical · Laboratory Test Abbreviations

Range of results expected in healthy people, conventionally the central 95 percent of values (2.5th to 97.5th percentiles) from a reference population. By definition about 1 in 20 healthy people falls outside it for any single test, which is why mildly abnormal results are common.

Example: Value flagged H but just above the RI; repeat in three months.

Often called the reference range or "normal range". With 20 independent tests, a healthy person has roughly a 64 percent chance of at least one flagged result. Intervals depend on method, population, age, sex and pregnancy, and CLSI guideline EP28 describes how labs should establish or verify them. Clinical decision limits, such as HbA1c 6.5 percent, are set differently from reference intervals.

3. Reserved instance

Technology & Computing · Cloud Computing Abbreviations

A billing commitment in which a cloud customer agrees to use a certain type of virtual machine or database for one or three years in exchange for a large discount, up to roughly 70 percent off on-demand prices.

Example: Buy three-year RIs for the database servers, since they run around the clock.

AWS introduced reserved instances in 2009, and Azure and Google offer similar commitments. AWS Savings Plans, launched in 2019, give comparable discounts with more flexibility across instance types. Unused reservations are wasted spend, which FinOps teams watch closely.

More US state abbreviations

OH – Ohio
OK – Oklahoma
OR – Oregon
PA – Pennsylvania
SC – South Carolina
SD – South Dakota
TN – Tennessee
TX – Texas

See all 51 US state abbreviations →

More laboratory test abbreviations

Retic – Reticulocyte count
RF – Rheumatoid factor
RFP – Renal function panel
Rh – Rhesus (D antigen)
RPR – Rapid plasma reagin
SG – Specific gravity
SGOT – Serum glutamic-oxaloacetic transaminase
SGPT – Serum glutamic-pyruvic transaminase

See all 135 laboratory test abbreviations →

Edited by the AbbreviationList.com team. Spotted an error or a missing meaning? Contact us.

This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.

RI