Who it is for
Anyone doing quick fitness arithmetic, such as a person setting a calorie target or checking a BMI figure without opening a separate tool.
AI Connectors · Healthcare & Life Sciences
WeightWise
Fitness calculators for BMI, body fat, and calorie needs
Overview
What WeightWise does
WeightWise from Layer 3 Labs gathers a set of standard health calculations into a single ChatGPT app. It covers body mass index, an estimate of body fat percentage, ideal weight ranges, and daily energy requirements expressed as BMR and TDEE.
These are calculations that have circulated in fitness literature for decades. What the app changes is the interface. Rather than loading a web form and filling in fields, a person asks in conversation and the figure comes back.
The described function is calculation rather than tracking, so the output is a number based on the inputs given at the time of asking.
What stands out
It groups four related calculations that normally sit on four different websites behind one request.
Availability
Where WeightWise is listed
WeightWise is listed in the ChatGPT apps directory only. Layer 3 Labs has no connector under the same domain in the Claude directory; 392 of the 3,150 products here are on both marketplaces, and this is not one of them.
ChatGPT apps are built on MCP, and the same server can back a Claude connector, so the absence is a distribution decision rather than a technical one.
ChatGPT listing
In the ChatGPT apps directory
- Developer
- Layer 3 Labs
- Filed under
- Healthcare
- Listed since
- June 2026
- Authentication
- Authenticates when installed
- Policies published
- Privacy policy · Terms of service
- Official listing
- Open in ChatGPT
- Snapshot
- August 2026
Example prompts from the listing
- What's my Body Mass Index (BMI)?
- What's my ideal weight for my age?
- What's my body fat percentage?
Nearby
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This is an independent catalogue entry compiled by Node8 from WeightWise's public marketplace listing as it stood in August 2026. Listing facts come from the marketplaces; the comparisons against the rest of the directory and any live-endpoint measurements are Node8's. Node8 is not affiliated with Layer 3 Labs, and inclusion here is not an endorsement.
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