Please do not forget to give us some feedback on how much your new Segwit supporting signature campaigns are saving you and your participants some Bitcoins from the reduced fees. Thanks.
Not needed. You can calculate this yourself. Fees for SegWit TXs: size (excl. witness) + witness size/4 = total size * fee-rate. Fees for legacy TXs: size * fee-rate. For a regular 1 in, two outs transaction of ~226 bytes * 409 sat/byte =
for a transaction of 226 bytes: 0.00092434.
A SW (1 in two outs) TX would be ~180 bytes * 409/sat/bytes: 0.00073620 BTC.
The more SW inputs you have (as opposed to legacy ones), the savings are greater. Let's see what happens when consolidating.
Legacy - 20 in, 1 out: ~3004 bytes, 0.01228636 BTC (178.6$).
SW - 20 in, 1 out: ~2046 bytes, 0.00836814 BTC (121.4$).