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DNS TTL Calculator

Calculate DNS TTL impact on propagation, caching, and query load

Time-to-live in seconds for your DNS records. Common values: 300 (5 min), 3600 (1 hr), 86400 (24 hr).
seconds
Total DNS queries per day from all clients for this record.
queries/day
The type of DNS change affects recommended TTL. Migration: low TTL pre-change. Failover: very low for fast switching. Load balance: moderate.
The TTL you are considering changing to. Leave as-is to see impact of current TTL.
seconds

Results

Max Propagation Time (current)
Max Propagation Time (new)
Cache Hit Ratio (current)%
Cache Hit Ratio (new)%
DNS Query Load Change
Recommended TTLseconds
How it works: DNS propagation worst case = current TTL. Cache hit ratio depends on query frequency relative to TTL. Lower TTL increases authoritative server load but enables faster failover. Recommended: 30s for failover, 60s pre-migration, 300s for load balancing, 3600s for stable records.