http://p2pnanphwyo2smf3khhjjkmfxll7h2ptmj4iwrbjklsk2wx66m5m7oad.onion/calculate-share-time
Do note this time will vary (can get shares sooner, or later, even way later), depending on your luck, and changing difficulty of the pool due to increase / reductions in hashrate. For lower hashrate, this average is what statistically will be achieved long term.