What grades are considered elementary school?

What grades are considered elementary school? I’m specifically wondering if the grade range varies by country or region—like whether it typically starts with kindergarten and goes up to fifth or sixth grade, or if some systems include middle school elements. Also, what ages do these grades usually encompass, and how do elementary school grades differ from preschool (pre-K) or middle/high school? I’m trying to understand the standard progression in the United States versus other countries, and any key variations or exceptions I should be aware of.

Elementary school generally encompasses the following grades in the United States:

1. Kindergarten (K): Typically the first year of formal schooling, for children around age 5-6.
2. First Grade (1st): Ages 6-7.
3. Second Grade (2nd): Ages 7-8.
4. Third Grade (3rd): Ages 8-9.
5. Fourth Grade (4th): Ages 9-10.
6. Fifth Grade (5th): Ages 10-11.
7. Sixth Grade (6th): Ages 11-12 (included in elementary school in some districts, often forming the start of middle school in others).

Common Structure Variations:

• K-5 Elementary: This is the most common structure in the United States. Elementary school includes Kindergarten through Fifth Grade. Sixth Grade typically begins middle school.
• K-6 Elementary: This structure is less common than K-5 but still found in many districts. Elementary school includes Kindergarten through Sixth Grade. Seventh Grade begins middle school.
• K-4 Elementary + Intermediate Elementary: Some districts split elementary education further. Kindergarten through Fourth Grade might be considered "elementary school," while Fifth and Sixth Grade form a separate "intermediate elementary" or "upper elementary" level before middle school.

Key Points:

• Age Range: Elementary school generally serves children roughly between the ages of 5 (Kindergarten) and 11 (6th grade if included in elementary).
• Terminology: It is also frequently referred to as "primary school" or "grade school."
• Followed By: Upon completion of elementary school, students typically transition to middle school (grades 6-8 or 7-8) or junior high school (grades 7-8 or 7-9).
• Start: Kindergarten is almost universally considered the starting point of elementary education in the US.