User Research Cost Calculator: AI Interviews vs Traditional (2026)

The Bottom Line

A single moderated user interview costs €90 to €260 all-in in 2026 once you add recruiting, moderator time, transcription, and analysis. AI-moderated platforms like Koji bring that down to €1 per text interview and €3 per voice interview, with reports generated automatically: a text interview is 1 credit, a voice interview is 3, and a credit costs €1 (a little less in larger credit packs). For a typical 30-interview discovery study, traditional methods land between €2,700 and €7,800, while running the same study on Koji costs about €40 to €100.

This calculator walks through the real line items so you can build an honest budget, or justify a switch to AI-moderated research.

What Goes Into the Cost of a User Interview

Most teams underestimate research spend because they only count the obvious items. The real cost stack has six layers:

1. Participant incentive: €25 to €150 per session depending on persona seniority
2. Recruiting fee: €40 to €120 per participant via panel platforms. On Koji there is no platform fee: bring your own audience, or approve a per-respondent quote in credits from Panel recruit before you launch
3. Scheduling and coordination: 30–45 minutes of researcher time per slot
4. Moderator time: 60 minutes per session plus 30 minutes of prep
5. Transcription: €0.10 to €1.50 per minute, or 4–6× hours of researcher review
6. Analysis and synthesis: typically equal to or greater than the interview time itself

Traditional research budgets often only show line items 1 and 2, then surprise teams when items 3–6 consume the rest of the quarter.

Per-Interview Cost: Traditional vs AI

Traditional moderated interview (mid-market, B2B SaaS persona)

Koji AI-moderated interview

Every Koji plan is priced at €1 per included credit:

Annual billing on Insights and Interviews gives you two months free. Voice interviews are on Interviews and Enterprise; text interviews are on every plan. When you need more credits than your plan includes, buy a credit pack: 50 credits for €50, 100 for €95, or 250 for €225, or any amount from 10 to 1,000 credits, with 5% off 51 to 200 credits and 10% off 201 to 500. You only ever pay for the conversations that bring insights. For team-wide deployments, or anywhere SSO, single-tenant infrastructure, or a signed DPA is required, the Enterprise plan is typically the better structure.

Calculator: 30-Interview Discovery Study

Let us run the math on a common scenario: 30 user interviews to validate a new feature.

Traditional (low estimate)

• Recruiting: 30 × €40 = €1,200
• Incentives: 30 × €25 = €750
• Researcher time (3h/interview avg): 90h × €60 = €5,400
• Transcription: 30 × 60min × €0.10 = €180
• Total: €7,530

Traditional (mid estimate)

• Recruiting + incentives: €4,500
• Researcher time + analysis: €5,400
• Transcription + tooling: €600
• Total: ~€10,500

Koji, text interviews

• 30 text interviews × 1 credit = 30 credits
• 2 report refreshes × 5 credits = 10 credits
• 40 credits: €40. One month of Insights (29 credits) plus a small top-up, or one month of Interviews (79 credits) with 39 left over

Koji, voice interviews

• 30 voice interviews × 3 credits = 90 credits
• 2 report refreshes × 5 credits = 10 credits
• 100 credits: €100, or €95 as a single 100-credit pack. On the Interviews plan, one month's 79 credits plus a small pack covers it

That is roughly a 75× to 260× cost reduction depending on mode and whether you compare to the low or mid traditional estimate. And you finish in days, not weeks.

Where the AI Savings Actually Come From

The biggest cost drivers in traditional research are researcher time and recruiting overhead, not the participant incentive. Koji removes both:

• Self-serve interview link. Share one link and dozens of participants can interview themselves in parallel. No scheduling, no calendar tag, no rescheduling.
• AI moderator. A Koji interview runs like a real conversation: the AI asks the question, listens, and follows up with up to three probing questions per topic, depending on the follow-up depth you set for each question. That replaces a researcher sitting on each call.
• Auto-transcription + auto-analysis. Every conversation is transcribed, themed, and mapped to your structured questions automatically. The themes, quotes, and per-question distributions are ready in real time.
• Quality-gated billing. Only conversations that score 3 or higher on the quality check consume credits. If a participant abandons after 30 seconds or types nonsense, no credit is charged.

For structured questions (NPS, willingness-to-pay, ranking, etc.), Koji also aggregates per-question distributions automatically, so your synthesis time on quantitative questions drops to near zero.

Recruiting Cost: AI Saves You Here Too

The panel-recruit model charges €40 to €120 per participant on top of the incentive, and that is pure overhead. You do not need your own audience. If you have customers, users, employees or a list, send them the interview link, embed it in your product, or let Koji call them. If you do not, open Panel recruit, describe who you want to hear from, and Koji finds them across 130+ countries. You see the price per completed interview in credits before you launch, you can soft-launch 10% first, and you only pay for interviews that pass the quality check. Recruiting, interviewing, analysis and the report all happen in one study, so nothing is exported, re-uploaded or re-tagged on the way. Quoting is free; launching is on paid plans. And because Koji interviews are async and self-serve, your own channels are cheap too:

• In-product link to existing users (free)
• Email list invitation (free, except small CRM costs)
• Community / Slack / LinkedIn outreach (free)
• Paid ads to a custom landing page (typically €5–€20 per qualified completion)

Koji also includes screening questions. You add them to the study brief and mark which answers qualify or rule someone out; every participant answers them before the interview starts, whatever route they came in by, and anyone who does not qualify is turned away. This replaces the panel platform's screening fee for many B2C and prosumer studies.

When Traditional Research Still Wins

Let us be honest about the tradeoffs. Traditional moderated interviews are still the right call when:

• You need high-empathy ethnographic depth with body language and a moderator reading the room
• Your participants are regulated personas (e.g., specific medical specialists) that a panel cannot target, where a specialist recruiter is the only path
• You are running a single high-stakes interview with an executive where fees pale next to the strategic value

For everything else (discovery, feature validation, NPS root-cause, willingness-to-pay, customer journey mapping, churn analysis, message testing), AI-moderated interviews on a platform like Koji are dramatically cheaper and faster.

How to Estimate Your Own Budget

Use this five-step framework to build a defensible 2026 research budget:

1. List your studies for the quarter. A typical product team runs 4–8 studies per quarter.
2. Pick your sample size per study. 8–15 for early discovery, 25–50 for validation, 100+ for quantitative segments.
3. Choose the modality. Text mode for higher volume and async; voice for nuanced, conversational depth.
4. Calculate Koji cost. Studies × interviews per study × 1 credit (text) or 3 credits (voice), plus 5 credits per report refresh, at €1 per credit.
5. Compare to traditional. Multiply your interview count by €280 (low) or €450 (mid) to see what you would otherwise spend.

For many teams, Koji's Interviews plan at €79/month is the right fit: 79 credits a month covers 79 text interviews or 26 voice interviews, adds voice, and includes 3 seats. Text-only teams can start on Insights at €29/month (29 credits). On annual billing (€790 or €290, two months free), a full year of research on Interviews costs about as much as two or three traditional moderated interviews.

FAQ Snapshot

• What does each Koji credit cost? €1. Plans are priced at €1 per included credit, and packs of more than 50 credits take 5% to 10% off. You only ever pay for the conversations that bring insights.
• Do I pay for failed interviews? No. Only conversations scoring 3 or higher on the quality check consume credits.
• Are voice and text interviews priced the same? No: text = 1 credit, voice = 3 credits.
• What does report refresh cost? 5 credits per refresh, billed only when you regenerate analysis.

Related Resources

• Plan Comparison Guide: credits, packs, and plans explained
• Structured Questions Guide: the question types that drive auto-aggregation
• How to Automate User Research: operating an AI-first research practice
• Koji vs UserTesting: head-to-head feature and pricing comparison
• Generating Research Reports: what real-time report aggregation looks like
• How the Quality Gate Works: why you only pay for useful interviews

Further reading on the blog

• Koji vs UserTesting: AI-Powered vs Panel-Based Research (2026): an honest comparison of AI-native interviews vs panel-based testing

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