This guide is an introduction to the World Health Organization Health Economic Assessment Tool for Cycling (HEAT for cycling). It is intended to be read alongside the tool, which is available to download as an Excel spreadsheet. The tool has been produced to illustrate the principles outlined in the WHO document Methodological guidance on the economic appraisal of health effects related to walking and cycling and to assist anyone who wishes to conduct an economic appraisal of the health effects related to increased cycling. It is designed to complement existing tools for economic appraisals of transport interventions which have traditionally tended to focus on other issues such as emissions or congestion. The tool will produce an estimate of the mean annual benefit (per cyclist; per trip; and total annual benefit) due to reduced mortality as a result of cycling. It can be applied in a number of situations: - when planning a piece of new cycle infrastructure. It will allow the user to model the impact of different levels of cycling and attach a value to the health benefit resulting from an estimated level of cycling when the new infrastructure is in place. This can be compared to the costs to produce a benefit: cost ratio (and help make the case for investment), or as an input into a more comprehensive economic appraisal; - to value the mortality benefits from current levels of cycling, such as to a specific workplace, across a city or in a country; - to provide input into more comprehensive economic appraisals, or prospective health impact assessments. For example to estimate the mortality benefits from achieving national targets to increase cycling or to illustrate potential cost consequences to be expected in case of a decline of the current levels of cycling.