How much does simultaneous interpretation cost — AI vs human in 2026

Simultaneous interpretation has been the standard for multilingual events since the Nuremberg trials — and so has its pricing model: interpreters paid by the day, equipment rented by the event, costs that scale linearly with language count. The model has not fundamentally changed in 80 years.

AI translation has introduced a fundamentally different pricing model: language-hours. Instead of billing by the interpreter-day, platforms charge per output language per hour of use. This article breaks down both approaches with real numbers so event planners can make informed budget decisions. For a broader comparison of the two approaches, see real-time translation vs simultaneous interpretation.

What simultaneous interpretation actually costs

Interpreter fees

Interpreters charge $500–$1,200 per day, depending on language pair, geographic location, and subject-matter expertise. Two interpreters are required per language — they rotate every 20–30 minutes to prevent the fatigue-induced errors that set in after sustained concentration. This means a single language channel costs $1,000–$2,400 per day in interpreter labor.

Common pairs (English–Spanish, English–French) typically fall in the $500–$800/day range per interpreter. Less common pairs (English–Khmer, Finnish–Japanese) command $900–$1,200/day — or are simply unavailable on short notice, requiring months of advance recruitment.

A two-day conference with three target languages requires six interpreter-days:

3 languages × 2 interpreters × $700/day = $4,200 in interpreter fees alone — before a single piece of equipment is rented.

Equipment and venue costs

The physical infrastructure adds significantly to the bill:

Item	Cost range
Soundproof interpreter booth (rental)	$1,500–$5,000 per booth
Receiver headsets	$5–$15 per unit × audience size
Audio routing, wiring, technician	$1,000–$3,000
Shipping and installation	$500–$2,000

A three-language event with 200 attendees: 3 booths + 200 receivers + technician = $8,000–$15,000 in equipment for a single event.

Hidden costs

The line items above do not capture the full picture:

• Advance booking: 4–8 weeks for common language pairs, 3+ months for rare pairs. Late bookings carry premium surcharges.
• Interpreter preparation: speakers’ scripts, specialized glossaries, and rehearsals — either billed separately or embedded in higher day rates.
• On-site technician: required for the full duration of the event, not just setup.
• Post-event logistics: collecting, inventorying, charging, and accounting for receiver headsets — with loss and damage typically billed to the organizer.

What AI translation costs

AI translation eliminates the interpreter labor and physical equipment that dominate traditional costs. Instead, pricing is based on compute — specifically, the cloud services that power the speech-to-text, translation, and text-to-speech pipeline.

The language-hour model

AI translation platforms use a billing unit called the language-hour: 1 output language × 1 hour = 1 language-hour. A two-hour talk with three output languages consumes 6 language-hours. Audience size does not affect cost — only the number of active language tracks matters. A session with 5 listeners costs the same as one with 350, as long as the language count and duration are identical. For a detailed explanation of the model, see the language-hour pricing model.

Pricing by plan

Plan	Monthly cost	Language-hours included	Effective $/lang-hr	Max listeners	Max languages
Free	$0	2 (lifetime)	—	25	3
Starter	$39	12	$3.25	75	5
Pro	$129	50	$2.58	200	8
Max	$449	200	$2.25	350	25
Enterprise	Custom	Unlimited	—	Unlimited	225+

Monthly plans allocate language-hours on the billing date. Unused hours expire at the end of the cycle — there is no roll-over. Each paid plan includes a hidden safety buffer (Starter: +2 hrs, Pro: +5 hrs, Max: +10 hrs) so live sessions are never cut off mid-event. See plans and quotas for full plan details.

What drives the cost

The per-language-hour cost breaks down across three cloud services:

• Speech-to-text (Deepgram Nova-3): ~$0.46/hr per language track
• Translation (Google Cloud): ~$0.02–$0.08/hr depending on tier
• Text-to-speech (Google Cloud TTS): ~$0.79/hr per audio language

Total pipeline cost: ~$1.27–$1.33 per language-hour. WebRTC media routing (self-hosted LiveKit) adds $0 — it is covered by server infrastructure and scales with SFU capacity, not per-listener billing. There is no per-attendee charge, no headset rental, and no minimum order.

Side-by-side comparison

The following table applies typical rates to common event scenarios, comparing the all-in cost of traditional interpretation against AI translation on the Max plan ($449/month, 200 language-hours included):

Scenario	Traditional interpretation	AI translation (Max plan)
2-day conference, 3 languages, 200 attendees	$12,000–$25,000	$449/month (200 lang-hrs)
1-hour webinar, 5 languages, 500 viewers	$4,000–$8,000	5 lang-hrs (~$12 from plan)
Weekly town hall, 2 languages, 100 employees	$2,000–$4,000 per event	Included in $39/month Starter
3-day summit, 8 languages, 1,000 delegates	$40,000–$80,000	$449/month + usage

When the cost math favors AI

• More than 3 target languages are needed — each additional language under traditional interpretation adds a full interpreter pair ($1,000–$2,400/day) plus another booth ($1,500–$5,000)
• Events recur weekly or monthly, allowing a subscription to amortize across multiple sessions — a $129/month Pro plan covers roughly 50 language-hours
• Audience size is large enough that headset distribution and collection become a logistical burden (200+ attendees)
• Events are short (1–2 hours) where minimum day-rates for interpreters are disproportionate to the actual service time
• Total interpretation budget is under $5,000 — roughly the cost of a single-language, single-day traditional setup

When traditional interpretation is worth the cost

Traditional interpretation is not obsolete — it remains the correct choice for specific categories of events where the cost premium is justified by the requirements:

• Legal proceedings requiring certified, sworn accuracy
• Diplomatic or political events where nuance, tone, and register are critical
• Only 1–2 language pairs are needed and qualified interpreters are readily available
• The venue already has permanent interpretation infrastructure installed

The bottom line

Traditional simultaneous interpretation costs $3,000–$25,000 per event and scales linearly — every additional language adds interpreters, equipment, and logistics. AI translation costs $2.25–$3.25 per language-hour with near-zero setup and supports over 200 languages without advance booking.

The crossover point is typically around 3–4 languages, or any event with recurring multilingual needs. Below that threshold, traditional interpretation may make sense where certified accuracy is required. Above it, AI translation is the economically rational choice — and for organizations running regular events, the savings compound month over month.

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Planning a multilingual event and want to estimate the cost? Start a free session to see how language-hour pricing works in practice — or review plans and quotas for specific plan details.