diff --git a/AK/NumberFormat.h b/AK/NumberFormat.h
index 7a2d1a681a7..0f172ed3bb0 100644
--- a/AK/NumberFormat.h
+++ b/AK/NumberFormat.h
@@ -32,10 +32,10 @@
 namespace AK {
 
 // FIXME: Remove this hackery once printf() supports floats.
-static String number_string_with_one_decimal(float number, const char* suffix)
+static String number_string_with_one_decimal(u64 number, u32 unit, const char* suffix)
 {
-    float decimals = number - (int)number;
-    return String::format("%d.%d %s", (int)number, (int)(decimals * 10), suffix);
+    int decimal = (number % unit) * 10 / unit;
+    return String::format("%llu.%d %s", number / unit, decimal, suffix);
 }
 
 static inline String human_readable_size(size_t size)
@@ -43,10 +43,10 @@ static inline String human_readable_size(size_t size)
     if (size < 1 * KiB)
         return String::format("%zu B", size);
     if (size < 1 * MiB)
-        return number_string_with_one_decimal((float)size / (float)KiB, "KiB");
+        return number_string_with_one_decimal(size, KiB, "KiB");
     if (size < 1 * GiB)
-        return number_string_with_one_decimal((float)size / (float)MiB, "MiB");
-    return number_string_with_one_decimal((float)size / (float)GiB, "GiB");
+        return number_string_with_one_decimal(size, MiB, "MiB");
+    return number_string_with_one_decimal(size, GiB, "GiB");
 }
 
 }
diff --git a/AK/Tests/TestNumberFormat.cpp b/AK/Tests/TestNumberFormat.cpp
index fb9619ead5f..f78e87bbebe 100644
--- a/AK/Tests/TestNumberFormat.cpp
+++ b/AK/Tests/TestNumberFormat.cpp
@@ -98,7 +98,7 @@ TEST_CASE(fraction_MiB)
 TEST_CASE(border_MiB_GiB)
 {
     EXPECT_EQ(human_readable_size(1000 * MiB), "1000.0 MiB");
-    EXPECT_EQ(human_readable_size(1024 * MiB - 1), "1024.0 MiB"); // TODO
+    EXPECT_EQ(human_readable_size(1024 * MiB - 1), "1023.9 MiB");
     EXPECT_EQ(human_readable_size(1024 * MiB), "1.0 GiB");
     EXPECT_EQ(human_readable_size(1024 * MiB + 1), "1.0 GiB");
 }
@@ -114,9 +114,9 @@ TEST_CASE(fraction_GiB)
     EXPECT_EQ(human_readable_size(1154272461), "1.0 GiB");
 
     EXPECT_EQ(human_readable_size(1181115968), "1.0 GiB");
-    EXPECT_EQ(human_readable_size(1181115969), "1.1 GiB"); // TODO
-    EXPECT_EQ(human_readable_size(1181116000), "1.1 GiB"); // TODO
-    EXPECT_EQ(human_readable_size(1181116006), "1.1 GiB"); // TODO
+    EXPECT_EQ(human_readable_size(1181115969), "1.0 GiB");
+    EXPECT_EQ(human_readable_size(1181116000), "1.0 GiB");
+    EXPECT_EQ(human_readable_size(1181116006), "1.0 GiB");
     // 1024 * 1024 * 1024 * 1.1 = 1181116006.4
     EXPECT_EQ(human_readable_size(1181116007), "1.1 GiB");
     EXPECT_EQ(human_readable_size(1202590842), "1.1 GiB");
@@ -124,9 +124,9 @@ TEST_CASE(fraction_GiB)
 
 TEST_CASE(extremes_4byte)
 {
-    EXPECT_EQ(human_readable_size(0x7fffffff), "2.0 GiB"); // TODO
+    EXPECT_EQ(human_readable_size(0x7fffffff), "1.9 GiB");
     EXPECT_EQ(human_readable_size(0x80000000), "2.0 GiB");
-    EXPECT_EQ(human_readable_size(0xffffffff), "4.0 GiB"); // TODO
+    EXPECT_EQ(human_readable_size(0xffffffff), "3.9 GiB");
 }
 
 template<int>
@@ -149,10 +149,10 @@ void actual_extremes_8byte<8>()
     EXPECT_EQ(human_readable_size(0x800000000ULL), "32.0 GiB");
     EXPECT_EQ(human_readable_size(0x10000000000ULL), "1024.0 GiB");
 
-    // Ehh, too bad.
-    EXPECT_EQ(human_readable_size(0x7fffffffffffffffULL), "-2147483648.-2147483648 GiB");
-    EXPECT_EQ(human_readable_size(0x8000000000000000ULL), "-2147483648.-2147483648 GiB");
-    EXPECT_EQ(human_readable_size(0xffffffffffffffffULL), "-2147483648.-2147483648 GiB");
+    // Oh yeah! These are *correct*!
+    EXPECT_EQ(human_readable_size(0x7fffffffffffffffULL), "8589934591.9 GiB");
+    EXPECT_EQ(human_readable_size(0x8000000000000000ULL), "8589934592.0 GiB");
+    EXPECT_EQ(human_readable_size(0xffffffffffffffffULL), "17179869183.9 GiB");
 }
 
 TEST_CASE(extremes_8byte)