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 as low as €1 per text interview and €3 per voice interview at the annual rate (€2 and €6 pay as you go), with reports auto-generated: a text interview is 1 credit, a voice interview is 3, and a credit costs €1.00 to €2.00 depending on how you buy. 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 €80 to €200.

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
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

A credit's price depends only on commitment: €2.00 pay as you go, €1.82 down to €1.33 in one-time packs (€100 to €2,000), about €1.20 on monthly plans (Starter €199 for 165 credits, Pro €499 for 415, Scale €999 for 830), and exactly €1.00 on annual plans with all credits granted on day one. That annual rate is where the €1 text interview and €3 voice interview come from. You are never tied to a subscription. There is no overage. You pay as you go, and you only ever pay for the conversations that bring insights. For team-wide deployments above ~100 interviews per month, or anywhere SSO, single-tenant infrastructure, or a signed DPA is required, the Enterprise plan (from €500/month or €6,000/year) 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: €80 pay as you go, covered by the €100 pack (55 credits, with 15 left over), or €40 at the annual rate

Koji, voice interviews

• 30 voice interviews × 3 credits = 90 credits
• 2 report refreshes × 5 credits = 10 credits
• 100 credits: about €190 (a €100 pack plus 45 credits pay as you go), or €100 flat at the annual plan rate of €1.00 per credit

That is a 40× to 130× cost reduction depending on mode and how you compare to the low or high end of traditional methods. 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 eliminates both:

• Self-serve interview link. Share one link and dozens of participants can interview themselves in parallel. No scheduling, no Calendly 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 (configured by maxFollowUps in the question definition). 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 hit the quality gate (score 3 or higher) 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 additionally auto-aggregates per-question distributions — meaning 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 — that is pure overhead. Because Koji interviews are async and self-serve, you can recruit through cheaper channels:

• 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 screener questions — a configurable intake form that filters participants by role, segment, or any custom attribute before the interview begins. 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) where panel recruiting 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, faster, and more rigorous.

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 or 3 credits) × €1 + plan fee.
5. Compare to traditional. Multiply by €280 (low) or €450 (mid) to see what you would otherwise spend.

For most teams, Koji's Starter plan at €199/month covers 165 credits: 55 voice interviews or 165 text interviews, enough for several full studies per month. Annualized at €1,990 with all 1,990 credits upfront at €1.00 each, a full year of research costs about as much as four traditional moderated interviews.

FAQ Snapshot

• What does each Koji credit cost? From €1.00 on annual plans up to €2.00 pay as you go. You choose the route. There is no overage, and you only ever pay for the conversations that bring insights.
• Do I pay for failed interviews? No — the quality gate ensures only scored 3+ conversations 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 6 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
• Plan Comparison Guide: choosing the right way to buy for your team

Further reading on the blog

• Koji vs UserTesting: AI-Powered vs Panel-Based Research (2026) — UserTesting averages $36,265/year for SMB teams. Koji starts free, then as low as €1 per qualified interview. Here's an honest comparison of AI-native interviews vs panel-base

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