Percent Complete in EVM: How to Measure Progress

<div class="ge-article-wrapper"><nav class="ge-toc" aria-label="Table of contents"><p class="ge-toc-label">In this article</p><ul class="ge-toc-list"><li><a href="#five-methods-of-measuring-percent-complete">Five Methods of Measuring Percent Complete</a></li><li><a href="#which-method-should-you-use">Which Method Should You Use?</a></li><li><a href="#worked-example-three-methods-three-different-stories">Worked Example: Three Methods, Three Different Stories</a></li><li><a href="#the-90-syndrome">The 90% Syndrome</a></li><li><a href="#common-mistakes">Common Mistakes</a></li><li><a href="#frequently-asked-questions">Frequently Asked Questions</a></li></ul></nav><article class="ge-article-body"><p>Percent complete is the proportion of budgeted work that's been finished: <a href="/en/earned-value/definitions/earned-value">Earned Value</a> divided by <a href="/en/earned-value/definitions/budget-at-completion">Budget at Completion</a>, expressed as a percentage. It's the single most important input in <a href="/en/earned-value">earned value management</a> and, without question, the most abused. Every <a href="/en/earned-value/definitions/cost-performance-index">CPI</a>, every <a href="/en/earned-value/definitions/schedule-performance-index">SPI</a>, every <a href="/en/earned-value/definitions/estimate-at-completion">EAC</a> downstream depends on this one number being honest. </p><p><strong>% Complete = EV / BAC x 100</strong></p><p>Or working backwards: <strong>EV = BAC x % Complete</strong></p><p>If BAC is £4,000,000 and the work package is 35% complete, EV = £1,400,000. Simple arithmetic. The hard part is determining that 35%. </p><p>This term is part of the <a href="/en/earned-value/definitions">earned value definitions glossary</a>. For the full formula reference, see the <a href="/en/earned-value/formulas">earned value formulas page</a>. </p><h2 id="five-methods-of-measuring-percent-complete">Five Methods of Measuring Percent Complete</h2><p>Not all percent complete measurements are equal. There are at least five common methods, and they'll give you different answers for the same work package. </p><pre class="ge-ascii-diagram ge-anim"> FIVE METHODS OF MEASURING % COMPLETE Applied to the same work package: M&amp;E First Fix, BAC = £2,000,000 Method 1: UNITS COMPLETE (objective) ───────────────────────────────────── Count: 680 of 1,600 distribution boards installed % Complete = 680 / 1,600 = 42.5% EV = £2,000,000 x 42.5% = £850,000 Method 2: COST RATIO (input-based) ───────────────────────────────────── Cost incurred to date: £760,000 % Complete = £760,000 / £2,000,000 = 38.0% EV = £2,000,000 x 38.0% = £760,000 Method 3: HOURS RATIO (input-based) ───────────────────────────────────── Hours spent: 14,400 of planned 32,000 % Complete = 14,400 / 32,000 = 45.0% EV = £2,000,000 x 45.0% = £900,000 Method 4: SUPERVISOR ESTIMATE (subjective) ───────────────────────────────────── Site supervisor says: "About 40%" % Complete = 40.0% EV = £2,000,000 x 40.0% = £800,000 Method 5: WEIGHTED MILESTONE (output-based) ───────────────────────────────────── Milestones achieved: Containment routes 15% ✓ (complete) Cable tray/basket 10% ✓ (complete) Distribution boards 15% ◐ (680/1600 = 42.5% of this milestone) Wiring first fix 30% ✗ (not started) Testing &amp; inspect 15% ✗ (not started) Commission prep 15% ✗ (not started) % Complete = 15 + 10 + (15 x 42.5%) = 31.4% EV = £2,000,000 x 31.4% = £628,750 SAME WORK. FIVE METHODS. FIVE ANSWERS. ┌──────────────────────────────────┐ │ Units complete: 42.5% £850K │ │ Hours ratio: 45.0% £900K │ │ Supervisor estimate: 40.0% £800K │ │ Cost ratio: 38.0% £760K │ │ Weighted milestone: 31.4% £629K │ └──────────────────────────────────┘ Range: £629K to £900K (£271K spread!) </pre><p>That £271,000 spread is the difference between a project that looks on track and one that's behind. And this is a single £2M work package. Scale that uncertainty across a £50M project with 12 packages and the aggregate error could be millions. </p><h2 id="which-method-should-you-use">Which Method Should You Use?</h2><p>There's a hierarchy. Always use the most objective method available. </p><div class="ge-table-wrap ge-anim"><table class="ge-table"><thead><tr><th>Priority</th><th>Method</th><th>When to Use</th><th>Reliability</th></tr></thead><tbody><tr><td>1st</td><td>Units complete</td><td>Work has countable, uniform outputs</td><td>Highest</td></tr><tr><td>2nd</td><td>Weighted milestones</td><td>Clear completion gates, non-uniform work</td><td>High</td></tr><tr><td>3rd</td><td>Physical measurement</td><td>Can survey/measure installed quantities</td><td>High</td></tr><tr><td>4th</td><td>Cost or hours ratio</td><td>No physical measurement possible</td><td>Medium</td></tr><tr><td>5th</td><td>Supervisor estimate</td><td>Last resort only</td><td>Lowest</td></tr></tbody></table></div><p>The key question: can you count something physical? If yes, count it. If no, can you define milestones? If yes, weight them. Only fall back to subjective estimates when nothing else works. </p><p>I'm genuinely harsh about this because I've seen the consequences. On a £35M data centre project, the M&amp;E subcontractor reported percent complete using supervisor estimates for 8 months. When the main contractor brought in an independent QS to verify, the actual physical progress was 12% lower than reported. Twelve percent on a £14M M&amp;E package is £1.68M of phantom earned value. The project CPI dropped from 0.96 to 0.82 overnight. The entire forecast had to be rewritten. </p><h2 id="worked-example-three-methods-three-different-stories">Worked Example: Three Methods, Three Different Stories</h2><span class="ge-worked-label">Worked Example</span><div class="ge-callout ge-anim"><p><strong>Scenario:</strong> £20M logistics warehouse, NEC4 Option C. Month 10 of an 18-month programme. The structural steelwork package (BAC = £3,600,000) is being measured.</p><br><p><strong>Physical facts:</strong> 2,400 tonnes of 3,200 tonnes erected. 156 of 210 bolt groups torqued. All ground floor steel complete, first floor 75% complete, roof trusses not started.</p><br><p><strong>Method 1: Tonnage installed (units complete)</strong></p><p>% Complete = 2,400 / 3,200 = <strong>75.0%</strong></p><p>EV = £3,600,000 x 75.0% = <strong>£2,700,000</strong></p><br><p>But this assumes all tonnes are equal cost. They're not. Roof trusses are heavier but also require cranage at height, which is more expensive per tonne. The ground floor steel was lighter but installed faster.</p><br><p><strong>Method 2: Weighted milestones</strong></p><div class="ge-table-wrap ge-anim"><table class="ge-table"><thead><tr><th>Milestone</th><th>Weight</th><th>Status</th><th>EV Contribution</th></tr></thead><tbody><tr><td>Ground floor columns and beams</td><td>30%</td><td>Complete</td><td>30.0%</td></tr><tr><td>First floor columns and beams</td><td>25%</td><td>75% complete</td><td>18.75%</td></tr><tr><td>Second floor structure</td><td>20%</td><td>Not started</td><td>0%</td></tr><tr><td>Roof trusses</td><td>15%</td><td>Not started</td><td>0%</td></tr><tr><td>Connections and bolting</td><td>10%</td><td>156/210 = 74%</td><td>7.4%</td></tr><tr><td><strong>Total</strong></td><td></td><td></td><td><strong>56.15%</strong></td></tr></tbody></table></div><p>EV = £3,600,000 x 56.15% = <strong>£2,021,400</strong></p><br><p><strong>Method 3: Cost ratio</strong></p><p>Actual cost to date on steelwork: £2,520,000</p><p>% Complete = £2,520,000 / £3,600,000 = <strong>70.0%</strong></p><p>EV = £3,600,000 x 70.0% = <strong>£2,520,000</strong></p><br><p><strong>The verdict:</strong> The weighted milestone method (56.15%) is closest to reality. The tonnage method overstates progress because it doesn't account for the relative cost of remaining work. The cost ratio simply tells you how much money you've spent, not how much work you've done.</p><br><p>The difference between method 1 and method 2 is £678,600. That's the difference between a CPI of 1.07 (tonnage) and 0.80 (milestones) for this package. One says the steelwork is going brilliantly. The other says it's in trouble. Both used the same physical facts.</p></div><h2 id="the-90-syndrome">The 90% Syndrome</h2><p>Every experienced QS knows this one. A work package reaches "90% complete" and stays there for weeks. Sometimes months. </p><p>It happens because the first 90% of installation is straightforward production work. The last 10% is snagging, testing, remedial work, waiting for access, and all the awkward bits that take disproportionate effort. Subjective estimates tend to front-load perceived progress. The work feels 90% done. It's actually 70% of the way through the cost and time. </p><p>Physical measurement prevents this. If 900 of 1,000 units are installed, you're at 90% by units. But if the remaining 100 units are in restricted areas requiring scaffolding and permits, the cost to install them might be 25% of the total budget, not 10%. That's why weighted milestones outperform simple unit counts for non-uniform work. </p><h2 id="common-mistakes">Common Mistakes</h2><ol><li><strong>Using cost ratio as a proxy for physical progress</strong>: Spending 60% of the budget doesn't mean 60% of the work is done. If you're overspending (CPI < 1.0), cost-based percent complete overstates progress. If you're under-spending, it understates it. Cost ratio measures spend, not achievement. They're not the same thing.</li><li><strong>Averaging across trades</strong>: "The building is 65% complete" is meaningless. Complete at what? The structure might be 90% done while M&amp;E is at 30%. Report percent complete at the <a href="/en/earned-value/definitions/control-account">control account</a> level, not the project level.</li><li><strong>Not distinguishing weighted and unweighted units</strong>: 75% of piles installed doesn't mean 75% complete if the remaining piles are in a river and cost three times as much per pile. Weight your units by effort or cost, not just by count.</li><li><strong>Accepting round numbers without evidence</strong>: Any percent complete that ends in 0 or 5 is probably an estimate, not a measurement. "About 40%" is a guess. "42.5% based on 680 of 1,600 units" is data. Challenge every round number.</li><li><strong>Measuring input instead of output</strong>: Hours worked or money spent are inputs. Metres installed, units erected, and milestones achieved are outputs. EVM measures the value of work completed, not the effort expended. Using inputs as a percent complete proxy is circular logic that will always show CPI near 1.0.</li></ol><div class="ge-product-note ge-anim"><p><strong>How Gather helps.</strong> Gather's AI reads your site diaries daily and maps progress against your cost-loaded programme, giving you accurate earned value data without manual spreadsheet updates. <a href="https://gatherinsights.com/contact">Book a demo</a> to see it working on a live NEC4 project.</p></div><h2 id="frequently-asked-questions">Frequently Asked Questions</h2><h3>What's the difference between percent complete and percent spent?</h3><p><a href="/en/earned-value/definitions/percent-spent">Percent spent</a> is AC / BAC, how much of the budget you've consumed. Percent complete is EV / BAC, how much of the planned work you've actually delivered. If they're equal, CPI = 1.0. If percent spent exceeds percent complete, you're overspending. This distinction is the entire foundation of earned value. Confusing the two makes every metric downstream meaningless. </p><h3>How often should percent complete be updated?</h3><p>Monthly, aligned with your cost reporting and payment cycle. Some fast-paced programmes update fortnightly. The key is that the measurement must use the same methodology each period. If you measured by units last month, you measure by units this month. Switching methods mid-project breaks trend analysis. </p><h3>Can percent complete go backwards?</h3><p>In theory, no. In practice, yes, and it should, if you discover you overstated it. If an independent audit reveals that actual physical progress is 55% rather than the 63% reported last month, adjust it down. This is painful and it wrecks your CPI trend line, but reporting false progress is worse. Some teams use a "correction" entry rather than restating prior months, which preserves the trend history while fixing the current position. </p><h3>Is percent complete the same as percent of payment certified?</h3><p>No. Payment certification is a commercial process driven by contract terms, retention, defects, and timing. <a href="/en/earned-value/definitions/interim-valuation">Interim valuations</a> may not reflect true physical progress, they often lag or lead depending on the contract form. EVM percent complete must be based on physical measurement, not payment schedules. </p></article></div>