Prompt Engineering Cost Calculator

Calculate the true cost of iterative prompt development including API tokens and engineer labor time.

Prompt tokens per call

Completion tokens per call

Development iterations

Input price per 1M tokens ($)

Output price per 1M tokens ($)

Engineer hourly rate ($)

Minutes per iteration

Tab to move between fields

Total development cost ($)

$125.12

≈ 8 movie tickets

API cost ($)$0.12

Labor cost ($)$125.00

Total engineer hours1.67

Total tokens consumed16,000

API cost share (%)0.1%

Production cost per call ($)$0.01

Break-even production calls20,854

Labor Cost (%)99.9%

How to Use This Calculator

Enter the typical Prompt Tokens and Completion Tokens for your task to set the per-iteration token cost.
Set Development Iterations — the number of prompt variations you test (typical projects run 10–50 iterations).
Enter Input Price and Output Price per 1M tokens from your LLM provider's pricing page.
Set Engineer Hourly Rate (fully loaded) and Minutes per Iteration to capture the labor cost alongside API spend.
Review Total Development Cost, API vs. Labor cost split, and Break-Even Production Calls to justify prompt optimization investment.

How the result changes with Development iterations

Prompt tokens per call: System + user prompt tokens per iteration. Include system prompt, few-shot examples, and user query.
Completion tokens per call: Expected output/completion tokens per iteration.
Development iterations: Number of prompt variations tested during development. Typical projects: 10-50 iterations.
Input price per 1M tokens ($): API cost per 1M input tokens. GPT-4o: $2.50, Claude Sonnet: $3.
Output price per 1M tokens ($): API cost per 1M output tokens. GPT-4o: $10, Claude Sonnet: $15.
Engineer hourly rate ($): Fully loaded hourly cost for the prompt engineer.
Minutes per iteration: Average time spent crafting, testing, and evaluating each prompt iteration.

Total development cost ($): Combined API + labor cost for prompt development.
API cost ($): Total API token cost across all iterations.
Labor cost ($): Engineer time cost across all iterations.
Total engineer hours: Total time spent on prompt development.
Total tokens consumed: Input + output tokens used across all iterations.
API cost share (%): Percentage of total cost from API calls vs. labor.
Production cost per call ($): API cost per production call once the prompt is finalized.
Break-even production calls: Number of production calls to amortize the development cost.

Identify Input Parameters
4 parameters
Prompt tokens per call = 500, Completion tokens per call = 300, Development iterations = 20, Input price per 1M tokens ($) = 3 = 7 input(s) provided
Calculate Total development cost
Total development cost = totalApiCost + laborCost
125.12 = $125.12
Calculate API cost
API cost = apiCostPerIteration * iterations
0.12 = $0.12
Calculate Labor cost
Labor cost = totalHours * engineerHourlyRate
125 = $125