AI Model Cost Comparison: Opus vs Sonnet - How Much Can You Save?
Real test data showing how much you can save monthly by switching from Opus to Sonnet.
🕐 Updated: 2026-03-12
AI Model Cost Comparison: Opus vs Sonnet - How Much Can You Save?
Last Updated: 2026-03-12
Key Findings
| Model Combo | Monthly Cost (Est.) | Savings |
|---|---|---|
| Opus 4.6 × Active Use | ~$47/week | - |
| Sonnet 4.6 × Same Usage | ~$21/week | 55% |
Based on typical community user scenarios
How Costs Are Calculated
AI model costs depend on:
- Model Selection - Opus vs Sonnet vs Haiku
- Usage - Conversation frequency, context size, thinking mode
- Output Length - Longer responses cost more
Formula
Daily Cost ≈ (input tokens × input price + output tokens × output price) × daily conversationsReal Comparison
Scenario: 50 daily conversations, average 2000 input tokens, 500 output tokens
| Model | Input Price | Output Price | Daily Cost | Weekly Cost | Monthly Cost |
|---|---|---|---|---|---|
| Opus 4.6 | $5/M | $25/M | ~$0.88 | ~$6.15 | ~$26.4 |
| Sonnet 4.6 | $3/M | $15/M | ~$0.53 | ~$3.71 | ~$15.9 |
| Haiku 4.5 | $1/M | $5/M | ~$0.18 | ~$1.24 | ~$5.3 |
Important Discovery: 4.6 Version Cost Gap Narrowed
According to Reddit user testing:
“Opus 4 vs Sonnet 4 had a 5x cost differential so it was an easy call: route the important stuff to Opus, everything else to Sonnet. With 4.6, that gap collapsed to 1.6x. At the same time, Sonnet 4.6 is now competitive or better on several tool-call tasks.”
This means Sonnet 4.6’s cost-performance ratio has significantly improved - choosing Sonnet for daily use is now more cost-effective.
When to Use Which Model?
Use Opus For:
- Complex code refactoring
- Long-form writing/translation
- Deep reasoning tasks
- Maximum comprehension needed
Use Sonnet For:
- Daily coding conversations
- Medium complexity tasks
- Balancing quality and cost
Use Haiku For:
- Simple Q&A
- Quick information lookup
- Low priority tasks
💰 Real Cases From the Community
“I used to burn $47/week on Opus, switched to Sonnet and now it’s $16/week. Totally sufficient.” — Reddit r/ClaudeAI
“Sonnet 4.6 is enough for daily development, only use Opus for refactoring.” — Reddit r/ClaudeCode
How to Choose the Right Model
Modify the default model in your AI configuration:
{
"agents": {
"defaults": {
"model": "sonnet"
}
}
}Or use model aliases:
opus→ Claude Opus 4.6sonnet→ Claude Sonnet 4.6haiku→ Claude Haiku 4.5
Next Steps
Want to learn more about cost optimization? Check out:
Auto-updated by AI · Source: Reddit