Hey everyone,
Like most of us building AI apps right now, I’ve been heavily debating whether to migrate my stack from OpenAI over to DeepSeek.
The headline is always "It's 10x cheaper!", but when you actually sit down to calculate your specific use case—factoring in input tokens, output tokens, context windows, and prompt caching—the math gets annoying really fast. I found myself running complex Excel spreadsheets just to figure out if the migration effort was actually worth the API savings.
I realized a lot of founders and devs are probably doing the exact same manual math.
So over the weekend, I built a fast, free, no-BS calculator to solve this: ByteCalculators: DeepSeek vs OpenAI Cost Optimizer
What it does:
You plug in your estimated daily active users and average context size (Inputs/Outputs).
It instantly calculates your Monthly Recurring Cost (MRC) for OpenAI models (GPT-4o, GPT-5 Mini, etc.) vs. DeepSeek V3.
It shows you the exact dollar amount you will save per month by switching.
It’s completely free, no ads, no sign-ups. Just pure math for builders.
Since I was recently invited as an early contributor here, I really wanted to share this with the CoderLegion community first.
I’d love your brutal feedback! Does the math check out for your current AI workloads? Are there any other models you’d like me to add to the comparison?
Cheers!