Semantic Cache Savings Calculator
See how a semantic cache cuts repeat-query cost.
With the default inputs, $2,100.00/month saved — 35.0% cache hit rate avoids LLM calls. Enter your own numbers below to recompute instantly; the full step-by-step math is shown under the worked example.
Results update automatically as you type.
- Cost / query (miss)
- $0.0100
- Base monthly cost
- $6,000.00
- Cache hit rate
- 35.0%
- Saved / month
- $2,100.00
A semantic cache serves answers to similar past queries without calling the model. Enter your query cost, volume and expected hit rate to see the monthly savings.
How this is calculated
Monthly savings = queries per day × 30 × hit rate × cost per query (cache miss). A semantic cache serves answers to meaning-similar past queries without calling the model, so every cache hit avoids a full query cost.
Is this a good result? What to do next
The saving is driven entirely by hit rate, which depends on how repetitive your traffic is — FAQ and support see high hit rates; open-ended chat sees little. Be realistic: an optimistic hit rate overstates savings, and stale cache entries can hurt answer freshness.
Typical planning ranges
- FAQ / support traffic
- high hit rate
- Open-ended chat
- low hit rate
- Savings
- hit rate × volume × cost/query
Ranges are typical planning figures to sanity-check your result, not authoritative benchmarks. Your numbers will vary with use case, volume, and vendor.
How to improve this number
- Cache high-frequency, stable questions.
- Tune the similarity threshold to balance hits vs wrong answers.
- Expire entries so cached answers stay fresh.
Common mistakes
- Assuming an optimistic hit rate before measuring it.
- Serving stale cached answers when the underlying data changed.
When to use a different approach
For exact-prefix caching of prompts, use the prompt caching savings calculator. For per-query RAG cost, use the RAG query cost calculator.
Worked example (defaults)
With the default inputs above, here is the result:
- Cost / query (miss)
- $0.0100
- Base monthly cost
- $6,000.00
- Cache hit rate
- 35.0%
- Saved / month
- $2,100.00
Frequently asked questions
What is a semantic cache?+
A cache keyed by meaning (embeddings) rather than exact text, so paraphrased repeat questions hit the cache.
What hit rate is realistic?+
Depends on how repetitive your traffic is — FAQs and support see high hit rates; open-ended chat sees less.
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