TTFB Target Results

Recommended TTFB Target

Network Latency

Server Processing

Note: This is a heuristic estimate. Actual performance may vary based on infrastructure, CDN, and application architecture.

Understanding TTFB Targets

Why TTFB Matters

Time to First Byte (TTFB) measures the time between the browser's request and receiving the first byte of the response. It's a critical metric because:

It represents the total round-trip time including DNS, TCP, TLS, and server processing
Poor TTFB directly impacts user perception of site speed
It affects subsequent loading phases like parsing and rendering
Google's Core Web Vitals consider TTFB in their overall performance assessment

How to Use This Calculator

Select your performance goal based on Core Web Vitals thresholds
Choose your page complexity to account for server processing needs
Adjust the distance slider based on your primary user locations
Review the calculated target and breakdown

Practical Examples

Scenario	Performance Goal	Complexity	Distance	Target TTFB
Marketing Site (US)	Good	Simple	500 km	400-600 ms
E-commerce (Global)	Needs Improvement	Medium	2000 km	600-800 ms
Web App (Regional)	Good	Complex	1000 km	500-700 ms

Reference: Core Web Vitals TTFB Guidance

Rating	TTFB Range	Description
Good	0-600 ms	Fast, meets user expectations
Needs Improvement	600-1000 ms	Average, room for optimization
Poor	Over 1000 ms	Slow, requires immediate attention

Frequently Asked Questions

What factors affect TTFB the most?

Network latency, server processing time, database queries, and backend application performance are the primary factors. CDN usage and caching strategies can significantly improve TTFB.

How accurate are these estimates?

These are heuristic estimates based on typical web performance patterns. Actual results may vary based on specific infrastructure, application architecture, and real-world network conditions.

Should TTFB targets differ by region?

Yes, users farther from your servers will experience higher network latency. Consider setting regional targets or using global CDNs to minimize geographical impact.

Formulas & Assumptions

Network Latency: Estimated at 1ms per 100km (speed of light in fiber) + 50ms overhead

Server Processing: Simple: 100-200ms, Medium: 200-400ms, Complex: 400-600ms

Performance Goals: Based on Core Web Vitals thresholds with buffer for consistency

Budget Allocation: TTFB typically consumes 20-40% of total loading budget

Rounding: Results rounded to nearest 50ms for practical target setting

TTFB Target Calculator

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TTFB Time to First Byte Target Calculator

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