For CTO · CFO · CIO

AI Build vs Buy Calculator.

Six weighted inputs, two scoring modes, live confidence meter, macro scenario stress-tests, side-by-side risk register, and sensitivity tornado. Inputs stay in your browser. No save, no send. Share via copy-link (state encoded in URL) or print to PDF for your committee.

Your inputs

Slide each one. Verdict + confidence update live. Defaults are mid-of-the-road.

Capability match of off-the-shelf vendor0 = far from your need · 100 = solves it cleanly 60

Integration complexity with your stack0 = drop-in · 100 = months of plumbing 50

Data sensitivity (PHI · CUI · trade-secret)0 = fully public-shareable · 100 = cannot leave premises 40

Time-to-value urgency0 = year+ ok · 100 = must ship in 30 days 55

Available eng capacity for the build0 = no headroom · 100 = a team waiting 35

Loaded 3-year cost to build in-houseeng salary × headcount × 3 + infra + opportunity cost

3-year cost of vendor (license + integration + ops)annual subscription × 3 + onboarding + internal support

Verdict

—

Confidence—

Build

Buy

Score composition

How each dimension contributes to Build vs Buy.

Cost comparison (3-year)

Loaded build cost vs vendor cost over the 3-year window.

If you BUILD, risks to budget

If you BUY, risks to budget

Sensitivity tornado

Each row shows what happens to the Build − Buy score gap if you slide that input ±20 from its current value (±20% for costs). Bigger bar = more sensitive. Direction shows which side benefits.

Move favors BUILD Move favors BUY

The math, openly

Build score = (100 − capability) × 0.18 + sensitivity × 0.22 + capacity × 0.20 + (100 − urgency) × 0.10 + costScoreBuild

Buy score = capability × 0.20 + (100 − integration) × 0.18 + urgency × 0.18 + (100 − sensitivity) × 0.14 + (100 − capacity) × 0.10 + costScoreBuy

costDelta = clamp(((costBuild − costBuy) / max(costBuild, costBuy, 1)) × 100, −100, 100). Positive when build is more expensive.

Confidence = clamp(round((|build − buy| / 30) × 100), 5, 100), proportional to the score gap.

Symmetric mode (default)costScoreBuild = −costDelta × 0.30 · costScoreBuy = +costDelta × 0.20. Higher build cost penalizes build AND rewards buy. The intuitive reading.

Literal modecostScoreBuild = +costDelta × 0.30 · costScoreBuy = −costDelta × 0.20. The original Kinetic Gain formula preserved verbatim. Note that in literal mode, higher build cost rewards build, preserved for transparency and so the math is auditable against the published spec.

No proprietary "magic." If you disagree with a weight, slide the input to compensate. This is a starting point, not a final answer.