Sum forwarding CLTV deltas, final-hop delta and optional shadow blocks to estimate a Lightning route's timelock budget.
How it works
The calculator sums the forwarding cltv_expiry_delta values, the receiver's final CLTV delta, and any optional shadow/extra delta. Time conversion uses 10 minutes per Bitcoin block only as an approximation.
The formula
Total blocks = Σ forwarding deltas + final delta + shadow delta. The list represents route-hop deltas in blocks, not channel balances or fees.
Worked example
For forwarding deltas 40,40,40 plus final delta 18 and no shadow blocks, the total budget is 138 blocks, approximately 23 hours at 10 minutes per block.
For educational and technical analysis only. Not financial advice, wallet software, transaction signing, or a security audit. Protocol and wallet behavior can differ. Never enter a seed phrase, private key, xprv or wallet password into He-Sab or any website.
Frequently asked questions
What does this calculator calculate?
Sum forwarding CLTV deltas, final-hop delta and optional shadow blocks to estimate a Lightning route's timelock budget.
Should I enter a seed phrase, private key, xprv or wallet password?
No. These calculators do not need secret wallet material. Never paste a seed phrase, private key, xprv or wallet password into He-Sab or any website.
Is the result authoritative for moving real funds?
No. It is an educational technical estimate. Confirm results with current Bitcoin or Lightning software, specifications and a safe test environment before using real funds.