Which is more cost-effective, Claude 3.7 Sonnet or Claude Sonnet 5.5?

Based on 1M input + 1M output tokens, Claude 3.7 Sonnet costs $18.00/month versus Claude Sonnet 5.5 at $12.00/month. The cheaper option depends on your token volume and prompt-to-completion ratio. Use the interactive calculator on this page to enter your exact usage.

How accurate is this cost comparison?

List prices come from each provider's own pricing page and every model page shows when they were last verified. The capability scores are iOPTERA's editorial composites — informed by public benchmarks, not benchmark results themselves; the methodology page explains how they are set.

Which model scores higher on benchmarks?

Claude 3.7 Sonnet scores 90 in coding and 90 in reasoning benchmarks. Claude Sonnet 5.5 scores 97 in coding and 94 in reasoning. See the full 5-category breakdown in the Benchmark Comparison section above.

What are the context window sizes of Claude 3.7 Sonnet and Claude Sonnet 5.5?

Claude 3.7 Sonnet supports a 200K-token context window while Claude Sonnet 5.5 supports 1.0M tokens. A larger context window lets you process more text in a single API call.

Which model is faster for real-time applications?

Claude 3.7 Sonnet has a speed score of 88/100 and Claude Sonnet 5.5 scores 91/100 on our latency benchmark. For interactive chatbots and low-latency tasks, the higher speed score is preferable.

Can I calculate costs for my specific token volume?

Yes. Use the interactive cost calculator on this page. Enter your monthly token volume and adjust the prompt-to-completion ratio. You can also use presets for common scenarios like Customer Support Bots (~30M tokens/month) or Document Summarizers (~15M tokens/month).

Cost and performance comparison

Claude 3.7 Sonnet vs Claude Sonnet 5.5

Model AAnthropic

Claude 3.7 Sonnet

Capability score (editorial)90/100

Cost / 1M Tokens: $6.60; 70% in · 30% out mix; ≈ $7.26 for the same text, tokenizer included
Value Index (score÷cost): 12.4; Higher = better value

Speed: 88/100
Context: 200K
Tier: Smart Tier

Last list price before the model was retired.

Its tokenizer produces about 10% more tokens than OpenAI's for the same text, so the real cost runs higher than the list price suggests. This is an estimate: the tokenizer has not been measured yet.

How we verify prices

Model BAnthropic

Claude Sonnet 5.5

Capability score (editorial)94/100

Cost / 1M Tokens: $4.40; 70% in · 30% out mix; ≈ $6.29 for the same text, tokenizer included
Value Index (score÷cost): 14.9; Higher = better value

Speed: 91/100
Context: 1.0M
Tier: Smart Tier

List price from the Anthropic pricing page, verified October 12, 2026.

Its tokenizer produces about 43% more tokens than OpenAI's for the same text, so the real cost runs higher than the list price suggests. This is an estimate: the tokenizer has not been measured yet.

Check the source

How we verify prices

In-depth analysis

Claude 3.7 Sonnet vs Claude Sonnet 5.5: Detailed Comparison

Claude 3.7 Sonnet is Anthropic's mid-range-tier language model with a 200K-token context window, excelling at data extraction. Claude Sonnet 5.5 from Anthropic is a mid-range-tier model supporting 1.0M tokens in context, with standout performance in coding.

Price is not the deciding factor here. For the same text, Claude Sonnet 5.5 and Claude 3.7 Sonnet land within 13% of each other, which is inside the margin your own input/output ratio will move anyway. Pick on capability, context, or latency instead — the monthly bill will look much the same either way. Claude 3.7 Sonnet is priced at $3.00/M input tokens and $15.00/M output tokens. Claude Sonnet 5.5 costs $2.00/M input and $10.00/M output.

Claude Sonnet 5.5 turns the same text into about 30% more tokens than Claude 3.7 Sonnet, because their tokenizers differ — so comparing list prices per token understates what Claude Sonnet 5.5 costs. For the same text, split 70% input and 30% output and counted the way OpenAI's tokenizer counts it, Claude Sonnet 5.5 works out at about $6.29 per million tokens and Claude 3.7 Sonnet at $7.26. Every cost figure on this page includes that difference.

On iOPTERA's editorial scores, Claude Sonnet 5.5 leads with 97/100 for coding and 94/100 for reasoning, against Claude 3.7 Sonnet's 90/100 and 90/100.

Capability breakdown

Across the five core benchmark categories, here is how Claude 3.7 Sonnet and Claude Sonnet 5.5 stack up head to head:

coding

Claude Sonnet leads

reasoning

Claude Sonnet leads

data extraction

Claude Sonnet leads

creative tasks

Claude Sonnet leads

vision/multimodal

Claude Sonnet leads

Best model by task

coding: Claude Sonnet 5.5 wins with 97/100
reasoning: Claude Sonnet 5.5 wins with 94/100
data extraction: Claude Sonnet 5.5 wins with 94/100
creative tasks: Claude Sonnet 5.5 wins with 93/100
vision/multimodal: Claude Sonnet 5.5 wins with 92/100

Estimated monthly cost at scale

For 10M + 2M tokens of text a month (counted the way OpenAI's tokenizer counts), Claude 3.7 Sonnet runs about $66.00 while Claude Sonnet 5.5 runs about $57.20 — Claude Sonnet 5.5 saves roughly $8.80 (13%) every month.

What actually decides it

Both models come from Anthropic, so they share a tokenizer, an API surface, and a billing account. Switching between them is a model-string change and nothing else — no new SDK, no re-tokenizing your prompts to re-estimate cost, no second vendor to onboard. That makes routing between them far cheaper to implement than a cross-vendor split.

These are the same lab's model at the same tier, 19 months apart — so this is an upgrade question, not a choice between alternatives. Claude Sonnet 5.5 is the current entry; Claude 3.7 Sonnet is here because plenty of production traffic still runs on it. If you are starting something new there is little reason to pick the older one, and if you are already on it the question is whether the migration cost is worth the gain.

The context gap is the largest single difference on this pair: Claude Sonnet 5.5 takes 1.0M tokens against 200K for Claude 3.7 Sonnet, roughly 5.0x. That is the difference between feeding in a whole repository or a full contract set and having to chunk it. If your work involves documents you cannot split cleanly, this decides it on its own.

Throughput is close enough to ignore — 91/100 versus 88/100. Neither model will feel noticeably quicker in an interactive product, so latency is not a reason to choose between them.

With prices this close (13% apart), pick on fit rather than cost. Claude Sonnet 5.5 holds the benchmark edge; weigh that against where each one is weakest — vision processing and vision processing respectively — and use the calculator above with your own token mix.

What you actually pay

The list price is only the start. Prompt caching, batch processing and long prompts change the bill, and each provider sets them differently. Prices per 1M tokens.

Pricing terms beyond the list price, per 1M tokens
Pricing term	Claude 3.7 Sonnet	Claude Sonnet 5.5
List price (input / output)	$3.00 / $15.00	$2.00 / $10.00
Cached input	—	$0.105% of the input price
Batch API	—	50% off input and output
Long prompts	—	No surcharge across the 1M window
Input with 80% cache hits	—	$0.48

The last row assumes 80% of input tokens are read from the cache, as in a chat app that re-sends a long system prompt or RAG over the same documents. Cache-write and storage charges are not included.

Claude also bills cache writes: 1.25× the input price for a 5-minute cache, 2× for one hour.

Checked on October 8, 2026 against the pricing pages of Anthropic.

Capability scores

iOPTERA editorial scores across 5 categories — informed by public benchmarks, not measured by us

CategoryClaude 3.7Claude SonnetWinner

Coding

Reasoning

Extraction

Creative

Vision

Claude 3.7 Sonnet: 0 wins

Claude Sonnet 5.5: 5 wins

Claude Sonnet 5.5 leads overall

Speed Score

88/100vs91/100

ClaudeClaude

Context Window

200Kvs1000K

ClaudeClaude

What Is a Token?

Models don't read words — they process tokens.

A token is roughly 4 characters of English text (~¾ of a word). Your API bill is priced per million tokens — understanding this directly reduces your costs.

Short phrase

"Hello, world!"

4 tokens

Claude 3.7 Sonnet: $1.32
Claude Sonnet 5.5: $1.14

Business email

One typical email (~200 words)

~270 tokens

Claude 3.7 Sonnet: $89.10
Claude Sonnet 5.5: $77.22

Code file

50-line Python script

~400 tokens

Claude 3.7 Sonnet: $132.00
Claude Sonnet 5.5: $114.40

Prices shown are for 100,000 runs of each workload — one run costs a fraction of a cent on both Claude 3.7 Sonnet and Claude Sonnet 5.5, so the number only becomes meaningful at production volume. Input tokens only; add your output volume in the calculator below.

How to check your token usage

response.usage.total_tokens

Every API response includes a usage object. Sum total_tokens across all calls to get your monthly figure, then use the calculator below.

Your Cost Calculator

Enter your actual monthly token usage to see real savings

Quick Presets

Monthly Token Volume

30M tokens

Prompt / Completion Split

Prompt 70%Completion 30%

Claude 3.7 Sonnet

$217.80/mo

$2,613.60/yr

$3.00/M input$15.00/M output

Cheaper

Claude Sonnet 5.5

$188.76/mo

$2,265.12/yr

$2.00/M input$10.00/M output

Annual Savings

$348.48 saved per year

Claude Sonnet 5.5 cheaper · $29.04/mo

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