AI API Prompt Budget & Monthly Spend Forecaster
Forecast monthly and annual API infrastructure costs based on daily active users, requests per user, average prompt length, and cached token discounts.
Tool controls
1. Traffic & Usage Parameters
2. Model & Architecture Tuning
Applies 50% - 90% discount to cached input tokens on repeated system prompts and RAG contexts.
Used to compute SaaS gross margin after AI compute costs.
10,000 queries/day across active users
450M Input | 120M Output
Reduced input cost by 35%
What-If Cost Optimization Scenarios
See how your monthly burn changes if you route traffic or background workers to high-efficiency models.
| Model Architecture | Monthly API Burn | Annual Burn | Cost / User / Mo | Monthly Difference | Runway Impact |
|---|
Recommended Breakeven Subscription:
To maintain a healthy 75% gross SaaS software margin, charge at least $9.20/month per active subscriber.
Production Optimization Recommendation:
Use prompt caching and consider a dual-model tiering pattern: route 80% of classification and simple queries to a low-cost model (e.g. GPT-4o-mini or Gemini 1.5 Flash) and reserve flagship models for complex reasoning.
Informational & Educational Disclaimer
This tool is designed for informational and educational estimation purposes only. Calculations are based on user-provided inputs and standard mathematical formulas. For official tax, legal, or financial decisions, please consult certified professionals or official government publications.