Crap Calculator


Crisis Statement

With 2.5 billion people in the world lacking access to improved sanitation, and 1.1 billion of these practicing open-defecation, communities are constantly exposed to excreta. This results in very poor health and diarrheal disease that is the second leading cause of death in children under five. Individuals may perceive their contribution to this problem as small and isolated, yet harder to visualise is the cumulative effect of large quantities of open-excreta, which is significant and pervasive.


Needs Statement

The solution is to change behaviours towards sanitation. This can be done by sparking off emotions in people such as disgust of crap and raising awareness on the negative consequences of open defecation. Community-Led-Total Sanitation for instance has become a widely successful approach to increase community awareness about the consequences of open-defecation, and thereby “trigger a demand” for sanitation. Through a community meeting, individuals all acknowledge where they defecate in the open, which leads to an awareness that everyone is exposed to one another’s excreta. CLTS is designed for rural villages but similar approaches can be used in other contexts. In urban media-aware environments, phones could be a useful tool to raise and spread awareness via social media such as Facebook or Tweeter on the quantities of excreta we produce.

The need is to create a simple program that can actually estimate quantities of crap in the environment and present the total in a visual funny and appealing display such as a drawing or a graph of some sort that could be shared on social media platforms. The objective is to get viral! The tool could potentially compare volumes of crap a country, megacity or city produces in a year to something representing a large volume such as  football stadiums or cargo planes (1 year of Crap = X cargo planes), or compare weight of the crap produced to bags of rice. 1 year of Crap = X bags of rice in weight). This added level of disgust can strengthen the impact of the demand triggering process.

This program would use pre-set reference figures of the average quantity of crap a human produces in a year, population of major cities, density etc.

BONUS: It can also be used to show the value there is in waste. For example, there are often small entrepreneurs that collect sewage from pit latrines for proper disposal at treatment plants. They typically collect payment from customers or from the treatment plant. The calculator could estimate the potential profits to be turned from this waste through collection and/or re-use as fertilizer.


See examples of sanitation market initiatives:


CONTEXT: While CLTS has been more frequently used in rural areas, there is an increasing interest in using it in peri-urban and urban areas. This technology may be particularly appropriate in these contexts, where computers and smart phones and social media applications are frequently used by urban youth. This tool could also be used for people conducting CLTS or a general assessment of open-defecation.

DESIGN FEATURES: Ultimately, the program should be designed for computer and smartphones, be accessible online and offline, and have the ability to aggregate data from multiple communities.


Impact Statement

The expected outcomes are as follows:

  1.       Increase the “disgust” feeling toward crap to trigger demand for sanitation even more effectively. Can be measured through monitoring open-defecation in an effort to lead to (and remain) open-defecation-free communities or urban youth.
  2.       To support sanitation advocacy: The tool can be used to demonstrate to local and national leaders, as well as donors, the importance of providing community toilets, or supporting sanitation-related programs or businesses.
  3.       To promote a market in waste collection and treatment: With the bonus, the tool can show the value in waste (that is otherwise wasted!) by collecting it and treating it- and where appropriate, re-using it for fertiliser after treatment.


Short Description

A tool to calculate and visualise quantities of crap, to be used to trigger disgust of crap and reduce open-defecation


Author: Tremolet Consulting, GB
Problem category: Open defecation, Toilets, Urban
Tags: CLTS social media Smartphone application


  1. Hi everyone,
    One of the ways I have found to change behavior patterns (here in the south of France) was to make toilets (compost toilets) available at different fairs and external events, where people can try out clean odorless comfortable self-contained units.
    I have since made a business out of this and had over 1000 000 people go throw my rental toilets over the past 5 years.
    Here at Ecolette we believe that the reconstruction of the biomass and the protection of the water cycles can only be restored and maintained when everyone on this planet has access to safe ecological sanitation.
    (We are currently involved in projects in Argentina, Morocco, and will be present in India and Peru this winter)

  2. Interesting idea. We have some good citations for the quantity of excrement created by people (surprisingly hard to find accurate stats on that) up at’s latest post on the history of sewage. Combine that with average household water use and you’d get a solid estimate of sewage generated by households.
    Also check out a series of boxes we painted to represent the quantity of excrement produced by the average adult in a year. Surprisingly small when it’s not mixed with water.

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