AI Text-to-Speech (TTS) Cost Calculator

The calculator treats every TTS provider the same way: take the synthesis volume in characters, divide by 1,000,000, and multiply by the vendor's published $/1M-char price. Each price comes from the vendor pricing pages cited at the bottom of this page, hand-verified on 2026-05-12and stored alongside its source URL in the calculator's code.

If you want to hear what these voices actually sound like before committing to a paid API, the free AI Voice Generator renders short text to an MP3 in the browser — useful for sanity- checking pronunciation on Sinhala or Tamil script before you size a monthly bill here. And if AI voice is one line item in a wider model budget, the AI Image Generation Cost Calculator and AI Embedding Cost Calculator use the same USD-and-LKR, sources-cited methodology for the other halves of a typical AI stack.

The core formula is intentionally boring:

chars_per_month  = mode == "characters"
                     ? input_chars
                     : input_minutes × wpm × 5    // 5 chars/word
billable_chars   = apply_free_tier
                     ? max(0, chars_per_month − free_allowance)
                     : chars_per_month
monthly_usd      = (billable_chars / 1,000,000) × price_per_1M
monthly_lkr      = monthly_usd × usd_to_lkr_rate

The chars-per-word constant (5) follows the standard English measurement (Mayzner & Tresselt 1965: ~4.79 chars/word plus one space, rounded up) used by every major TTS vendor's own cost-estimator example. Override the words-per-minute input (default 150) to match your style — slow narration ≈ 130, conversational ≈ 150, fast ad-read ≈ 200.

ElevenLabs prices in credits, not characters. Each model publishes a credits-per-character rule (Multilingual v2 = 1 credit/char; Turbo v2.5 and Flash v2.5 = 0.5). For a given monthly volume, the calculator walks the published subscription plans (Free → Starter → Creator → Pro → Scale → Business) and picks the cheapest one whose monthly credit pool fits. The reported monthly cost is the plan's flat price; the "$/1M chars" column shows the effective rate on that plan:

effective_$/1M = plan_monthly_usd
                 ÷ (plan_credits ÷ credits_per_char)
                 × 1,000,000

Where a provider has no model in a given tier (Deepgram has no HD variant; OpenAI has no $4/1M budget tier; PlayHT bundles premium with voice cloning), the row is greyed out with a tooltip explaining why — never replaced with a fabricated number.

Free monthly allowances are jurisdiction-aware: Google's tier is permanent; AWS Polly's is first-12-months only on a new AWS account; Azure's F0 allowance is permanent; ElevenLabs Free is 10,000 credits/month forever. The toggle in the calculator lets you compare with and without these allowances applied.

Minutes ↔ characters round-trip self-test passes — the conversion is reversible at integer minute inputs.

Worked-example self-test (computed live on this page) — each line reconciles the formula above with the hand-derived numbers in the code header:

• ✓A · 800k chars · standard · OpenAI tts-1 → expected $12.00, got $12.00
• ✓A · 800k chars · standard · Google Neural2 (free covers) → expected $0.00, got $0.00
• ✓A · 800k chars · standard · Azure Neural Std (0.5M free) → expected $4.80, got $4.80
• ✓B · 250k chars · premium · OpenAI tts-1-hd → expected $7.50, got $7.50
• ✓B · 250k chars · premium · Polly Generative (100k yr1 free) → expected $4.50, got $4.50
• ✓C · 0 chars · standard · any provider → expected $0.00, got $0.00
• ✓D · 10M chars · budget · Google Standard (4M free) → expected $24.00, got $24.00
• ✓D · 10M chars · budget · Polly Standard (5M yr1 free) → expected $20.00, got $20.00
• ✓E · boundary 1,000,000 chars · Google Neural2 (1M free) → expected $0.00, got $0.00
• ✓F · 1,000,000,000 chars · standard · OpenAI tts-1 → expected $15000.00, got $15000.00
• ✓G · minutes mode · 30min × 150wpm = 22,500 chars · OpenAI tts-1 → expected $0.34, got $0.34
• ✓H · 250k chars · premium · ElevenLabs Multilingual v2 (Pro plan fits) → expected $99.00, got $99.00
• ✓I · 250k chars · standard · ElevenLabs Turbo v2.5 (Pro plan fits) → expected $99.00, got $99.00

Out of scope for v1: live vendor price scraping (brittle and ToS- restricted; quarterly hand-verification is more honest); voice quality benchmarks (this tool prices, it doesn't rank); custom / cloned voice training cost (bespoke per-vendor pricing); real-time streaming surcharges; self-hosted GPU TTS rental (Coqui XTTS, Piper, Kokoro on RunPod — different unit economics); music or sound-effect generation (Suno, Udio, ElevenLabs Sound Effects); and speech-to-text pricing — the sibling AI Audio Transcriber handles that side, in-browser.

• OpenAI — API Pricing (tts-1 $15/1M, tts-1-hd $30/1M chars)
• ElevenLabs — Pricing (Free, Starter, Creator, Pro, Scale, Business plans)
• ElevenLabs — Text-to-Speech API reference (per-model credit rules)
• Google Cloud Text-to-Speech — Pricing (Standard, Neural2/WaveNet, Studio, Chirp 3 HD)
• Azure AI Speech — Pricing (Neural Standard, Neural HD)
• Amazon Polly — Pricing (Standard, Neural, Long-form, Generative + AWS Free Tier)
• Deepgram — Pricing (Aura TTS)
• Cartesia — Pricing (Sonic Turbo, Sonic 2)
• PlayHT — Pricing (Creator $39/mo, Unlimited $99/mo)
• Central Bank of Sri Lanka — Daily indicative USD→LKR rates

Pricing was last cross-checked against each vendor's pricing page on 2026-05-12. The table is reviewed quarterly and whenever a vendor announces a tier change. Spotted a stale row? Email the address below — most fixes ship within 24 hours.