About the Olympic Games Sustainability Score
Hosting an Olympic Games involves years of construction, billions of dollars in public spending, and a promise that the event will leave a positive legacy rather than a trail of empty stadiums. Researchers who study Olympic sustainability — including the widely cited Oxford Saïd Business School cost studies (Flyvbjerg, Budzier, and Lunn) and academic legacy audits — boil this down to three measurable questions: how much new construction did the Games require, how far did the final bill run over budget, and how many venues found a real use after the closing ceremony. This calculator turns those three answers into a single 0–100 score.
The formula
Three sub-scores, each on a 0–100 scale, are averaged with equal weight:
- Venue reuse rate = (existing + temporary venues) ÷ (total venues) × 100. A Games that uses mostly existing arenas and temporary structures avoids stranded, single-use infrastructure. Paris 2024 reported roughly 95% of its venues were existing or temporary; Games with heavy new permanent construction score lower here.
- Cost-overrun ratio = final cost ÷ original bid budget. A ratio of 1.00 means the Games came in on budget; 1.31 means a 31% overrun. The score converts this to points by subtracting the overrun percentage from 100 (capped at 0–100), so a Games that comes in on or under budget scores 100, and one that doubles its budget scores close to 0. Flyvbjerg's research found the average Summer Games since 1960 overran its budget by about 213% (median 120%), with Winter Games averaging around 142% (median 118%) — the combined Summer+Winter average across all Games is 172%.
- Legacy-use rate = percentage of venues with a confirmed, funded post-Games use (professional sports tenant, public facility conversion, disassembly-and-resale plan, etc.), used directly as the 0–100 score.
Overall score = (venue reuse rate + budget score + legacy-use rate) ÷ 3. This is a transparent, equal-weighted average — not an official IOC metric — designed so every input is independently checkable against public bid books, organizing-committee reports, and post-Games audits.
Putting the inputs in context
- Montreal 1976 is the classic cautionary tale: the city took 30 years to pay off Olympic debt after costs ran roughly 720% over the original budget.
- Beijing's 2008 "Bird's Nest" stadium famously struggled to find a profitable post-Games tenant and now costs tens of millions annually in upkeep — a low legacy-use case despite architectural acclaim.
- Los Angeles 1984 and 2028 are frequently cited as high-reuse benchmarks: LA 2028 organizers planned to build zero new permanent venues, relying entirely on existing arenas, stadiums, and temporary structures.
- London 2012's Olympic Stadium was purpose-built with a documented conversion plan (it became West Ham United's home ground), an example of high legacy-use planning executed before the Games even opened.