Software Project Estimation Tools Compared (2026)

Software project estimation tools come in six kinds: spreadsheets with three-point ranges, relative sizing with velocity in Jira, time trackers that turn past hours into future budgets (Harvest), agency quoting suites (Scoro), parametric models (COCOMO II), and AI estimators that draft a breakdown from a brief (Keisan). Disclosure: Jishu Labs, which publishes this blog, makes Keisan.

No tool makes an estimate accurate by itself. Accuracy comes from decomposition, ranges and a multiplier measured against your own past projects, the method set out in how to estimate a software project without guessing. The tools differ in how much of that method they support. Prices below are list prices as of October 2026.

How do software project estimation tools compare in 2026?

Estimation tools split on two questions: who the estimate is for, and whether the tool learns from what projects actually took. Jira and Harvest record actuals; spreadsheets, COCOMO II and Keisan do not unless you feed results back in. Scoro links quotes to delivery and billing in one system, with quoted-versus-actual reporting on its top combination.

Is a spreadsheet still a good way to estimate a software project?

A spreadsheet is a good estimating tool when it enforces a method: one row per work item, optimistic, likely and pessimistic hours for each, and the PERT expected value, (O + 4L + P) / 6. Its weakness is that nothing enforces anything. Formulas drift, rates go stale, and every estimator ends up editing a different copy.

Spreadsheets cost nothing extra if your company already pays for Google Workspace or Microsoft 365, and they bend to any pricing model. They are also where estimating errors hide best, because a broken formula looks exactly like a working one.

• Best for: a team with a template it trusts and one person who owns that template.
• Choose it over Keisan when: your estimate structure is unusual, or you want control of every formula and will maintain it.

Is Jira with story points a project estimation tool?

Jira with story points is a forecasting tool for an existing team, not a quoting tool. The team sizes work in points, and Jira's velocity chart averages what it completed in recent sprints to predict what the next sprint can take. It cannot price a new client project, because a new engagement has no velocity history to convert points into time.

The velocity chart works in company-managed Scrum spaces and can chart story points, original time estimates, work item count or any numeric field. Jira is free for up to 10 users; Atlassian lists Standard at $8.48 and Premium at $15.56 per user per month as of October 2026.

• Best for: product teams forecasting how long an existing backlog will take.
• Choose it over Keisan when: the work is internal, the team is stable, and the question is when it will ship rather than what it will cost a client.

How does Harvest help with software estimates?

Harvest helps with estimates by recording what projects actually took. It is a time tracker, and every plan lets you set project estimates of hours and cost before kickoff and then track time against them. The gap between quoted and actual hours, measured across past projects, is the multiplier that makes the next estimate honest.

The Free plan covers one seat and two projects. Teams costs $11 per seat per month, or $9 billed annually; Enterprise costs $17.50, or $14 billed annually, and adds profitability reporting by client, project, task or team. Scheduling lives in a separate product, Harvest Forecast, which every plan can connect to.

• Best for: agencies and consultancies that bill by time and want quotes calibrated against real hours.
• Choose it over Keisan when: you need to know what past projects actually cost. Keisan does not track time.

When should an agency use Scoro for quotes?

Scoro suits agencies and consultancies that want quoting, delivery and invoicing in one system. Its Estimate app builds quotes and budgets with margin estimation, using a quote and budget builder, an estimation matrix and quote templates. The Quote to Cash combination is listed at $29 per user per month as of October 2026, with a five-user minimum.

Quoted-versus-actual reporting comes with Scoro's Advanced Financials, which is part of the End-to-end combination rather than Quote to Cash. Scoro is a full professional services platform, so adopting it for estimates means adopting its project, time-tracking and billing workflow too. A 14-day free trial needs no credit card.

• Best for: service firms of five or more people that want one record from quote to invoice.
• Choose it over Keisan when: you want quotes connected to delivery, time tracking and billing rather than a standalone estimate.

Is COCOMO II still useful in 2026?

COCOMO II is useful when an estimate has to be defended with a published model rather than judgement. Barry Boehm published the original COCOMO in 1981, and COCOMO II followed in 2000. The model converts software size, in source lines of code or function points, plus scale drivers and cost drivers into effort in person-months, schedule and cost.

An openly available web calculator built by Ray Madachy at the Naval Postgraduate School takes those inputs and returns effort, schedule, cost and a phase-by-phase breakdown. Its weakness for modern work is the input: estimating lines of code before design is a guess in its own right, and the model's default constants come from historical projects that predate AI-assisted coding.

• Best for: large, regulated or public-sector projects where a documented model is expected.
• Choose it over Keisan when: you can size the system in lines of code or function points and need a method an auditor will recognize.

What does Keisan do, and where does it fall short?

Keisan is the AI Project Estimation tool from Jishu Labs, at keisan.jishulabs.com. Jishu Labs describes it in one sentence: "Turn a plain-English project brief into a defensible, itemized cost and timeline estimate, built from your own rate cards in minutes." The Free plan generates itemized estimates; Pro costs $15 a month.

Each estimate breaks the brief into line items with role, hours and rate. The Free plan uses a default rate card and core scenario modeling. Pro adds custom rate cards with a blended rate, optimistic, likely and pessimistic scenarios with cost and timeline ranges, margin and profitability calculations, and a client-ready proposal exported as a PDF. What is a rate card? explains the input that matters most.

Its limitations are real:

• It does not track time. Keisan cannot compare an estimate with what the project actually took, so your calibration multiplier has to come from your own records or a time tracker such as Harvest.
• It is not a sprint-planning tool. It estimates in hours and cost, not story points, and it does not connect to Jira.
• An AI breakdown is a first draft. It can only itemize what the brief describes, so a vague brief produces an incomplete estimate that still looks precise.
• It is a young product, and custom rate cards, margin and PDF proposals require Pro. SSO and a self-host option are Enterprise only.

Which software estimation tool should you choose?

Choose by who the estimate is for. Internal backlog forecasts belong in Jira with velocity. Client quotes need hours, rates and margin, from a spreadsheet, Scoro or Keisan. Whatever produces the quote, record actual time somewhere, such as Harvest, because a multiplier measured from your own history improves accuracy more than any tool can.

• Forecasting a stable team's backlog: Jira with story points and the velocity chart.
• Quoting new client work quickly: Keisan or a well-kept spreadsheet template.
• Running an agency from quote to invoice: Scoro.
• Learning what projects really cost: Harvest, whatever you quote with.
• Defending an estimate to an auditor or public client: COCOMO II, alongside a bottom-up estimate.