diff --git a/src/main.rs b/src/main.rs
index b9e8250..963bded 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -25,7 +25,7 @@ extern crate num_bigint;
 use num_bigint::BigInt;
 
 extern crate num_traits;
-use num_traits::{ToPrimitive, Zero};
+use num_traits::{Zero};
 
 #[cfg(feature = "gpu")]
 extern crate ocl;
@@ -115,6 +115,7 @@ fn check_solution(params: &ThreadParams, key_material: [u8; 32]) -> bool {
             public_key,
             params.simple_output,
         );
+        params.attempts.store(0, atomic::Ordering::Relaxed);
         if params.limit != 0
             && params.found_n.fetch_add(1, atomic::Ordering::Relaxed) + 1 >= params.limit
         {
@@ -292,7 +293,7 @@ fn main() {
             .collect();
     }
     let matcher_base = PubkeyMatcher::new(ext_pubkey_req, ext_pubkey_mask);
-    let estimated_attempts = matcher_base.estimated_attempts();
+    let finding_chance = matcher_base.finding_chance();
     let matcher_base = Arc::new(matcher_base);
     let limit = args
         .value_of("limit")
@@ -333,7 +334,7 @@ fn main() {
         .map(|s| s.parse().expect("Failed to parse thread count option"))
         .unwrap_or_else(|| num_cpus::get() - 1);
     let mut thread_handles = Vec::with_capacity(threads);
-    eprintln!("Estimated attempts needed: {}", estimated_attempts);
+    eprintln!("Estimated attempts for 90% chance to find a match: {:.0}", -1.0_f64 / (1.0_f64 - finding_chance).log10());
     for _ in 0..threads {
         let mut key_or_seed = [0u8; 32];
         OsRng.fill_bytes(&mut key_or_seed);
@@ -435,7 +436,7 @@ fn main() {
         thread::spawn(move || loop {
             let attempts = attempts.load(atomic::Ordering::Relaxed);
             let estimated_percent =
-                100. * (attempts as f64) / estimated_attempts.to_f64().unwrap_or(f64::INFINITY);
+                100. * (1.0 - (1.0 - finding_chance).powf(attempts as f64));
             let runtime = start_time.elapsed();
             let keys_per_second = (attempts as f64)
                 // simplify to .as_millis() when available
diff --git a/src/pubkey_matcher.rs b/src/pubkey_matcher.rs
index 4e66033..c4b35c4 100644
--- a/src/pubkey_matcher.rs
+++ b/src/pubkey_matcher.rs
@@ -2,7 +2,6 @@ use std::cmp;
 
 use blake2::VarBlake2b;
 use digest::{Update, VariableOutput};
-use num_bigint::BigInt;
 
 #[derive(Clone)]
 pub struct PubkeyMatcher {
@@ -68,11 +67,11 @@ impl PubkeyMatcher {
         true
     }
 
-    pub fn estimated_attempts(&self) -> BigInt {
+    pub fn finding_chance(&self) -> f64 {
         let mut bits_in_mask = 0;
         for byte in &self.mask {
-            bits_in_mask += byte.count_ones() as usize;
+            bits_in_mask += byte.count_ones() as i32;
         }
-        BigInt::from(1) << bits_in_mask
+        2.0_f64.powi(-bits_in_mask)
     }
 }