# Budget Overrun 2026: Statistics, Source Studies and EVM Tools

> Independent reference and calculation hub for project budget overruns, grounded in the Flyvbjerg 16,000+ project database and the Standish CHAOS Report. PMI puts the share of projects over budget at 43%; for construction megaprojects it is 98% (McKinsey), 9 in 10 for infrastructure (Flyvbjerg), 69% for IT (Standish). Free EVM, EAC, contingency, PERT and reference-class-forecasting calculators, no signup.

## Overview

- [Budget Overrun 2026: Megaprojects Bust 98% of the Time](https://budgetoverrun.com): PMI says 43% of projects exceed budget. For construction megaprojects it is 98% (McKinsey). Infrastructure 9 in 10, IT 69%. Free EVM calculator, no signup.
- [Project Budget Overrun Statistics 2026: 43%, 28%, 69%, 98% by Sector](https://budgetoverrun.com/statistics): Cited 2026 budget-overrun statistics by industry: 43% of projects over budget (PMI), 9 in 10 infrastructure (Flyvbjerg), 69% IT (Standish), 98% megaprojects. Sources linked.
- [About BudgetOverrun.com](https://budgetoverrun.com/about): Who builds the site, why it exists, editorial principles, scope, and the corrections process. Independent, no vendor relationships.
- [Methodology](https://budgetoverrun.com/methodology): Publisher sources, calculation framework, EVM formula stack, reference class forecasting, refresh cadence, and the corrections process.

## Source studies (primary-source citation pages)

- [Flyvbjerg Project Database: Only 0.5% of Projects Deliver in Full](https://budgetoverrun.com/studies/flyvbjerg-megaproject-database): Bent Flyvbjerg's Oxford project database covers 16,000+ projects. 47.9% on budget, 8.5% on budget and time, 0.5% deliver promised benefits too. Category base rates, methodology and citation.
- [Standish CHAOS Report: 69% IT Project Failure Rate Explained](https://budgetoverrun.com/studies/standish-chaos-report): The Standish CHAOS Report tracks IT project success since 1994. CHAOS 2020 (Beyond Infinity): 31% successful, 50% challenged, 19% failed. Methodology, sample size, and full source link.
- [McKinsey IT Projects Study: 45% Over Budget, 56% Less Value](https://budgetoverrun.com/studies/mckinsey-large-it-projects): The McKinsey-Oxford study of 5,400 IT projects: 45% over budget, 7% late, 56% less value than predicted. Full citation, URL and methodology.
- [PMI Pulse of the Profession: Source for the 43% Over Budget Stat](https://budgetoverrun.com/studies/pmi-pulse-of-the-profession): The PMI Pulse of the Profession is the source for the often-cited 43% of projects over budget figure. Methodology, sample, and canonical URL.
- [Flyvbjerg & Budzier 2011: 27% Average IT Overrun, 1-in-6 Black Swans](https://budgetoverrun.com/studies/flyvbjerg-budzier-it-black-swans): The Flyvbjerg & Budzier study of 1,471 IT projects (Harvard Business Review, 2011): 27% average cost overrun, but one in six is a Black Swan with a 200% cost overrun and 70% schedule overrun.
- [GAO Weapon Systems Annual Assessment 2025 (GAO-25-107569)](https://budgetoverrun.com/studies/gao-weapon-systems-assessment): 106 major US weapon programmes, ~$2.4 trillion planned. Combined cost estimates for 30 continuing MDAPs rose $49.3bn in one year, $36bn of it Sentinel.
- [NASA Requirements vs Overrun Curve: 5-10% vs 20% Cost Effect](https://budgetoverrun.com/studies/nasa-requirements-overrun-curve): NASA studies show projects spending 5-10% of effort on requirements run ~50% over budget; projects spending 20% run only ~10% over. Source breakdown and citation.
- [The "53,000 Tech Projects, 63%" Statistic: Is It Real? (Source Trace)](https://budgetoverrun.com/53000-tech-projects-statistic): The viral claim that a study of 53,000 tech projects found 63% have hidden costs has no traceable primary source. We trace where it likely came from and give the real large-sample IT datasets to cite instead.

## Case studies (verified overrun records)

- [Sydney Opera House: 7M to 102M AUD, the 1,357% Overrun](https://budgetoverrun.com/case-studies/sydney-opera-house): 1957 winning entry AUD 7M, 1973 completion AUD 102M. 14x over budget and 10 years late. Hall's Great Planning Disasters analysis.
- [Boston Big Dig: 2.8B USD to 14.8B Final Cost (+429%)](https://budgetoverrun.com/case-studies/big-dig-boston): The Central Artery/Tunnel Project went from 2.8B USD (1985) to 14.8B (2007), 24bn including interest. Federal Highway and MassDOT data.
- [Berlin Brandenburg Airport (BER): 9 Years Late, EUR 7B Over Budget](https://budgetoverrun.com/case-studies/berlin-brandenburg-airport): BER opened 2020 instead of 2011, costing EUR 7.3B instead of EUR 2B. Causes, fire-protection scandal, and Bundesrechnungshof source data.
- [Crossrail (Elizabeth Line): 4 Years Late, 4B GBP Over Budget](https://budgetoverrun.com/case-studies/crossrail): Crossrail opened May 2022, 3.5 years late. Final cost 18.8bn GBP vs 14.8bn budget. NAO 2019 and 2022 reports on the software-integration failure.
- [California High-Speed Rail: 33B to 231B Cost Growth](https://budgetoverrun.com/case-studies/california-high-speed-rail): Sold to voters in 2008 at 33bn USD. The Draft 2026 Business Plan puts the original design at 231.3bn USD, or 126.2bn with right-sizing. HSRA and LAO source data.

## Sectors

- [Construction Budget Overruns: 9-in-10 Rate, 28% Over](https://budgetoverrun.com/construction): 9 in 10 infrastructure projects overrun by 28% on average (Flyvbjerg 2002). Phase risk, contract types, supply-chain data, prevention strategies.
- [IT Project Budget Overruns: 45% Over Budget, 69% Fall Short](https://budgetoverrun.com/it-projects): Large IT projects run 45% over budget; 69% are challenged or fail (Standish CHAOS 2020). McKinsey data, agile-vs-waterfall impact, why software estimation breaks down.
- [Government Budget Overruns: HS2, Crossrail, US Federal](https://budgetoverrun.com/government-projects): Half of public-sector IT projects overrun; overruns run ~3x private-sector peers (McKinsey). HS2, Crossrail, Universal Credit case studies.
- [Defense Project Budget Overruns: GAO 2025 Acquisitions Data](https://budgetoverrun.com/defense-projects): GAO assesses 106 major US weapon programmes investing nearly $2.4 trillion. In 2025 combined cost estimates rose $49.3bn in one year. F-35, Sentinel, Columbia, Ford-class.
- [Aerospace Project Budget Overruns: NASA, ESA & Launch Vehicles](https://budgetoverrun.com/aerospace-projects): JWST went from 500M to 10bn USD. SLS, Artemis, Mars Sample Return, Europa Clipper cost growth from NASA OIG and GAO reports. Per-mission overrun table.
- [Energy Project Budget Overruns: Nuclear, Oil & Gas, Renewables](https://budgetoverrun.com/energy-projects): Nuclear plants average 117% overrun (Sovacool 2014). Oil and gas 34% (Flyvbjerg). Solar and wind under 15%. Hinkley, Olkiluoto, Kashagan cases.
- [Healthcare IT Project Overruns: EHR Rollouts and NPfIT Lessons](https://budgetoverrun.com/healthcare-it-projects): EHR implementations routinely overrun. NHS NPfIT cost 10bn pounds. Cerner-VA EHR went from 16bn to 50bn. What predicts go-live overruns.
- [Infrastructure Megaproject Overruns: Rail, Road, Bridge, Tunnel](https://budgetoverrun.com/infrastructure-megaprojects): Rail averages 39% over budget, bridges 34%, roads 24% (Flyvbjerg). Per-mode data, the optimism-bias driver, and the worst examples by category.
- [Olympic Games Budget Overruns: Every Games Since 1960 Over Budget](https://budgetoverrun.com/olympics-budget-overruns): Every Olympic Games since 1960 has run over budget. Mean cost overrun across all Games is 172%. Tokyo 2020, Rio 2016, Sochi 2014, Beijing 2008 data.
- [Movie Budget Overruns: Hollywood Production Cost Overrun Cases](https://budgetoverrun.com/movie-budget-overruns): Cleopatra, Heaven's Gate, Waterworld, The Lone Ranger and Mortal Engines. Original vs final budgets, with trade-press sources.
- [12 Famous Budget Overruns in History: Comparison Table](https://budgetoverrun.com/famous-examples): 12 historic overruns ranked: Sydney Opera House (+1,357%), James Webb Telescope (+1,900%), Big Dig (+429%), HS2, Berlin Airport. Verified case studies.

## Concepts and methods

- [The Iron Law of Megaprojects: Over Budget, Over Time, Over and Over Again](https://budgetoverrun.com/iron-law-of-megaprojects): Bent Flyvbjerg's Iron Law explained. Nine out of ten megaprojects overrun. Definition, origin, the data, and the often-conflated figures.
- [Reference Class Forecasting Calculator: The Flyvbjerg Method](https://budgetoverrun.com/reference-class-forecasting): Apply HM Treasury Green Book optimism-bias uplifts to your estimate by project type. The Flyvbjerg method, with worked example.
- [Cone of Uncertainty: Boehm's Original Curve and How to Narrow It](https://budgetoverrun.com/cone-of-uncertainty): Early estimates are 4x out at concept and shrink to 1.25x at detailed design. Boehm's Cone of Uncertainty original 1981 data, with critique and updates.
- [Boehm's Cost-of-Change Curve: Does a Bug Really Cost 100x More Late?](https://budgetoverrun.com/cost-of-change-curve): The cost to fix a defect rises the later it is caught. Boehm & Basili (2001) put it near 100x after delivery, ~5x on small projects. The famous 1:10:100 'IBM' chart is unsourced; here is what is real.
- [7 Causes of Budget Overruns: Scope Creep, Estimates & More](https://budgetoverrun.com/causes): Scope creep (52%), poor estimates (70%), optimism bias, political pressure, vendor risk. Academic plus practitioner breakdown.
- [How to Prevent Budget Overruns: 12 Proven Strategies](https://budgetoverrun.com/prevention): Reference class forecasting, EVM monitoring, change control, contingency sizing. Evidence-based, no vendor sales pitch.
- [How to Deal With a Project Cost Overrun: 7-Step Recovery Plan](https://budgetoverrun.com/recovering-from-cost-overruns): Already over budget? Measure with EVM, forecast the final cost (EAC), calculate the recovery needed (TCPI), and decide whether to recover, re-baseline, or de-scope.
- [Who Pays for Budget Overruns? Contract Law Explained](https://budgetoverrun.com/legal-consequences): Contract types (lump-sum, cost-plus, GMP), variation claims, dispute resolution, contractor insolvency. General info, not legal advice.
- [Cost Overrun Insurance: Builder's Risk, Surety Bonds](https://budgetoverrun.com/insurance): Builder's risk, professional indemnity, surety bonds. What each policy covers, and the gaps, when projects exceed budget.

## Calculators and tools

- [EVM Calculator: CPI, EAC, VAC & TCPI Free Online Tool](https://budgetoverrun.com/calculator): CPI, SPI, EAC (3 methods), VAC, TCPI. Construction, IT and government presets. Formula reference and worked examples, no signup.
- [Earned Value Management Guide: CPI, SPI, EAC Formulas](https://budgetoverrun.com/earned-value-management): Complete EVM guide: CPI, SPI, EAC (3 methods), VAC, TCPI formulas with worked examples. Limitations explained. PMP-aligned notation.
- [Estimate at Completion Calculator (EAC): All 4 PMBOK Methods](https://budgetoverrun.com/estimate-at-completion-calculator): Enter BAC, EV, AC and PV to get all four PMBOK EAC forecasts side by side: BAC/CPI, AC+(BAC-EV), CPI x SPI, and bottom-up ETC.
- [Contingency Budget Calculator: Type-A vs Type-B Project Buffers](https://budgetoverrun.com/contingency-budget-calculator): AACE 40R-08 categories, percent ranges by project type, worked sizing example for type-A vs type-B projects.
- [Monte Carlo Simulation for Project Cost Risk: Worked Example](https://budgetoverrun.com/monte-carlo-simulation): Samples thousands of project futures from input distributions to produce P50, P80, P95 budgets. AACE method with worked example.
- [PERT Calculator: Three-Point Estimation Formula & Worked Example](https://budgetoverrun.com/three-point-estimation): Enter optimistic, most likely and pessimistic values to get E = (O + 4M + P) / 6, standard deviation, and confidence-weighted budget. PMBOK source.
- [Cost Overrun Formula: How to Calculate Budget Overrun (%)](https://budgetoverrun.com/cost-overrun-formula): Overrun % = (Actual Cost - Budgeted Cost) / Budgeted Cost x 100. Worked dollar examples, the EVM cost-variance version, and which baseline to measure against.
- [Free Budget Tracker Templates: EVM, Change Order, CCO](https://budgetoverrun.com/templates): Free copy-paste templates: project budget tracker, EVM status report, change order log, contingency calculator, post-project review. No signup.

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