BC ⇄ AD Year Difference

Compute the time between a BC/BCE year and an AD/CE year. Formula: D = BC + AD − 1 (no year 0).

Inputs

(Label only; values unchanged)
BC/BCE year must be ≥ 1.
(Label only; values unchanged)
AD/CE year must be ≥ 1.
Computed as D = BC + AD − 1 (there’s no year 0). Enter here (with any other field) to solve the third.
Difference must be ≥ 0.

Quick summary

Inputs
Time between
Also equals

Step-by-step derivation

Formula (no year 0): D = BC + AD − 1
Substitute: D = …
Solve: …
        

Actions

Reference table & sources

Notes
  • There is no year 0. 1 BC is followed immediately by AD 1.
  • Formula: D = BC + AD − 1, where D counts full years between the given years.
  • Naming equivalencies: BC ≡ BCE; AD ≡ CE (labels only; values unchanged).

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