At 15 requests/user/day (totaling 45,000,000 queries/mo), running Translation on Gemini 3.1 Flash Lite (OpenRouter) costs $419,906.25 / month ($4.199 / user / mo).
Translation for a 100,000 active users (high-volume consumer / enterprise) audience means 1,500,000 requests per day on average, each carrying 5,000 input and 5,500 output tokens at a 15% cacheable share — so the effective per-request cost on Gemini 3.1 Flash Lite (OpenRouter) is $0.009331, of which $7,593.75/mo comes back from prompt caching. Per active user that's $4.199/mo — the number to hold against your pricing tier and gross margin. Charging at least $20.995/user/mo keeps gross margin at or above 80%.
Quick answer
For 100,000 Active Users, Translation on Gemini 3.1 Flash Lite (OpenRouter) is modeled at 45,000,000 requests per month, costing $419,906.25 per month or $4.199 per active user.
Method & trust
This projection combines the selected active-user tier, requests per user per day, input/output tokens per request, and the modeled cache share. It is an operating estimate, not a provider invoice; production traffic and retries should be measured against it.
Total expected API invoice for 100,000 Active Users generating 45,000,000 queries.
Direct inference cost per MAU to model your SaaS pricing tiers and gross margins.
Savings generated by exploiting 15% cache hits on prompt context.
| Model | Provider | Monthly Spend (100,000 Active Users) | Cost / User / Mo | Annual Spend | Context Limit |
|---|---|---|---|---|---|
| Gemini 3.1 Flash Lite (OpenRouter) (Current) | $419,906.25 | $4.199 | $5,038,875.00 | 1,048,576 | |
| GPT-5.6 Luna | openai | $335,925.00 | $3.359 | $4,031,100.00 | 1,050,000 |
| GPT-5.4 mini | openai | $1,259,718.75 | $12.597 | $15,116,625.00 | 256,000 |
| GPT-5.4 nano | openai | $348,300.00 | $3.483 | $4,179,600.00 | 128,000 |
| GPT-4o mini | openai | $179,718.75 | $1.797 | $2,156,625.00 | 128,000 |
| Claude Haiku 4.5 | anthropic | $1,432,125.00 | $14.321 | $17,185,500.00 | 1,000,000 |
At 15 queries per user/day with Gemini 3.1 Flash Lite (OpenRouter), the estimated cost is $4.199 per monthly active user (MAU). Total monthly bill for 100,000 Active Users is $419,906.25.
Assuming a 15% cache hit rate on repeated system and context tokens, prompt caching saves $7,593.75 per month ($91,125.00/year) on Gemini 3.1 Flash Lite (OpenRouter).
With a direct COGS of $4.199 per user/month on Gemini 3.1 Flash Lite (OpenRouter), charging at least $20.995 per user/month ensures an 80%+ software gross margin.