Guidance

Impact assessment and options assessment calculator

Help for policy officials to calculate figures for impact assessments (IAs) and options assessments (OAs).

• From: Department for Business, Innovation, Science and Trade and Department for Business and Trade
• Published: 13 May 2013
• Last updated: 11 September 2026
  Show all updates

  1. 11 September 2026

     GDP deflators updated in impact assessment calculator spreadsheet. Discount rate updated in line with new HMT guidance.

  2. 21 May 2026

     Updated GDP deflators were added to the impact assessment calculator.

  3. 29 January 2026

     The impact assessment calculator and guidance updated for present value and price year 2026.

  4. 18 August 2025

     GDP deflators updated in impact assessment calculator speadsheet.

  5. 19 May 2025

     Impact assessment calculator (reforms 2023) ODS: updated to remove spurious data in Option 1 worksheet.

  6. 4 April 2025

     Impact assessment calculator (reforms 2023) ODS: updated GDP deflators to March 2025 figures.

  7. 6 February 2025

     Impact assessment calculator (reforms 2023) and Impact assessment calculator user guide (reforms 2023) updated. Impact assessment calculator and Impact assessment calculator guide deleted.

  8. 16 April 2024

     Attachments 'Impact assessment calculator (reforms 2023) and 'Impact assessment calculator user guide (reforms 2023)' to reflect 100 year extension.

  9. 31 October 2023

     Updated GDP deflators to those published on 30 Sep 2023.

  10. 19 September 2023

      Added Impact assessment calculator (2023 reforms). Added Impact assessment calculator guide (2023 reforms).

  11. 14 April 2023

      Updated Impact assessment calculator.

  12. 11 January 2023

      Impact assessment calculator and user guide updated.

  13. 26 October 2022

      GDP deflators updated.

  14. 29 July 2022

      Impact assessment calculator and user guide updated.

  15. 4 April 2022

      Replaced Impact assessment calculator file.

  16. 26 November 2021

      Updated calculator with the latest Gross Domestic Product (GDP) deflator figures.

  17. 28 July 2021

      Updated versions added

  18. 26 April 2021

      Impact Assessment calculator updated

  19. 8 December 2020

      Have updated the calculator document

  20. 1 October 2020

      IA calculator has been updated

  21. 6 May 2020

      Impact assessment calculator updated

  22. 12 March 2020

      IA calculator user guide

  23. 19 February 2020

      New IA template attached.

  24. 9 October 2019

      Updated calculator with new GDP deflator figures.

  25. 5 April 2019

      Updated calculator with new GDP deflator figures.

  26. 18 March 2019

      Updated to include latest GDP deflators - addition of user guide.

  27. 2 November 2018

      We have uploaded a version with updated GDP deflators (October 2018 version).

  28. 5 July 2017

      Calculator updated.

  29. 7 April 2017

      Calculator updated.

  30. 26 January 2017

      Calculator updated to reflect ONS latest release

  31. 6 October 2016

      Updated version of the calculator.

  32. 6 July 2016

      Calculator updated.

  33. 29 April 2016

      Calculator updated.

  34. 8 April 2016

      Calculator updated.

  35. 9 March 2016

      Calculator updated.

  36. 31 July 2015

      Calculator updated.

  37. 18 May 2015

      Calculator updated.

  38. 23 January 2015

      Calculator updated January 2015.

  39. 10 October 2014

      Calculator updated October 2014

  40. 2 July 2014

      Calculator updated July 2014.

  41. 4 April 2014

      Calculator updated.

  42. 10 January 2014

      Calculator updated.

  43. 3 October 2013

      Spreadsheet updated.

  44. 13 May 2013

      Updated version of impact assessment calculator released.

  45. 13 May 2013

      First published.

Documents

Impact assessment calculator (reforms 2023)

ODS, 368 KB

This file is in an OpenDocument format

This file may not be suitable for users of assistive technology.

Request an accessible format

If you use assistive technology (such as a screen reader) and need a version of this document in a more accessible format, please email digital@businessandtrade.gov.uk. Please tell us what format you need. It will help us if you say what assistive technology you use.

Impact assessment calculator user guide (reforms 2023)

ODT, 299 KB

This file is in an OpenDocument format

This file may not be suitable for users of assistive technology.

Request an accessible format

If you use assistive technology (such as a screen reader) and need a version of this document in a more accessible format, please email digital@businessandtrade.gov.uk. Please tell us what format you need. It will help us if you say what assistive technology you use.

Details

The calculator automatically generates the main figures needed by policy officials for their impact assessments and options assessments, using the profile of costs and benefits for each option.