How long was World War II?

World War II lasted 6 years (1939 – 1945) across 6 major phases.

Duration Overview

Duration

6 years

Start

1939 AD

End

1945 AD

Invasion of Poland / Phoney War 243 days

1939 AD – 1940 AD

Germany invades Poland. Britain and France declare war but little fighting in the West.

Fall of France / Battle of Britain 1 years

1940 AD – 1941 AD

Blitzkrieg conquers Western Europe. Britain stands alone. The Blitz.

Eastern Front Opens / Pearl Harbor 1 years

1941 AD – 1942 AD

Operation Barbarossa. Japan attacks Pearl Harbor. War becomes truly global.

Turning Points 1 years

1942 AD – 1943 AD

Stalingrad, Midway, El Alamein. Axis momentum halted.

Allied Advance 1 years

1943 AD – 1944 AD

Italy invaded. D-Day. Island-hopping in Pacific.

Victory in Europe & Pacific 1 years

1944 AD – 1945 AD

Germany surrenders May 8. Atomic bombs. Japan surrenders September 2.

That's 6 years — about 2192 days. Short enough that people alive at the start could remember the end.

How long was World War II?

6 years and 1 day (September 1, 1939 – September 2, 1945). The deadliest conflict in human history: 70-85 million dead.

When did World War II start and end?

World War II began in 1939 and ended in 1945, spanning 6 years.