Citation Impact Factor Calculator Formula

Understand the math behind the citation impact factor calculator. Each variable explained with a worked example.

Use the Citation Impact Factor Calculator

Formulas Used

Impact Factor

impact_factor = citations_year / articles_in_window

Avg Articles per Year

articles_per_year = articles_in_window / window_years

Variables

VariableDescriptionDefault
citations_yearCitations This Year to Articles in Window320
articles_in_windowArticles Published in Window80
window_yearsWindow (Years)2

How It Works

How Journal Impact Factor is Calculated

The impact factor (IF) measures how frequently articles from a journal are cited.

Formula

IF = Citations in Current Year to Articles Published in Prior Window / Total Articles in Window

The standard window is 2 years. A journal that published 80 articles in 2 years and received 320 citations to those articles has an IF of 4.0.

Context

  • IF > 10: High impact
  • IF 3-10: Good impact
  • IF 1-3: Moderate impact
  • IF < 1: Lower impact

    • Worked Example

    A journal published 80 articles in the last 2 years and received 320 citations to those articles this year.

    citations_year = 320articles_in_window = 80window_years = 2
    1. 01Impact factor: 320 / 80 = 4.000
    2. 02Articles per year: 80 / 2 = 40.0

    Frequently Asked Questions

    Who calculates official impact factors?

    Clarivate Analytics calculates the official Journal Impact Factor (JIF) published in Journal Citation Reports.

    Can impact factor be gamed?

    Yes, through editorial self-citation, review articles, and publication timing. This is why multiple metrics should be used.

    Is a higher impact factor always better?

    Not necessarily. Niche fields have lower citation rates. A specialized journal with IF 2.0 may be top-tier in its field.

    Ready to run the numbers?

    Open Citation Impact Factor Calculator