The mortage calculators are correct since when you first start paying a loan, your money goes first to the interest and then the principle. It can be a few years before you even really start to get to the principle on your mortage so you are paying interest still on the just about full amount of your principle. Let's look at a 30 year fixed at 7% on 150,000.
Amortization Table for $150000.00 borrowed on Mar 21, 2008
Month
Year 4
2008 5
2008 6
2008 7
2008 8
2008 9
2008 10
2008 11
2008 12
2008 1
2009 2
2009 3
2009
Payment ($) 997.95 997.95 997.95 997.95 997.95 997.95 997.95 997.95 997.95 997.95 997.95 997.95
Principal Paid ($) 122.95 123.67 124.39 125.12 125.85 126.58 127.32 128.06 128.81 129.56 130.32 131.08
Interest Paid ($) 875.00 874.28 873.56 872.84 872.11 871.37 870.63 869.89 869.14 868.39 867.64 866.88
Total Interest ($) 875.00 1749.28 2622.84 3495.68 4367.79 5239.16 6109.79 6979.68 7848.83 8717.22 9584.85 10451.73
Balance ($) 149877.05 149753.38 149628.98 149503.86 149378.02 149251.44 149124.11 148996.05 148867.24 148737.68 148607.36 148476.29
Month
Year 4
2009 5
2009 6
2009 7
2009 8
2009 9
2009 10
2009 11
2009 12
2009 1
2010 2
2010 3
2010
Payment ($) 997.95 997.95 997.95 997.95 997.95 997.95 997.95 997.95 997.95 997.95 997.95 997.95
Principal Paid ($) 131.84 132.61 133.38 134.16 134.95 135.73 136.52 137.32 138.12 138.93 139.74 140.55
Interest Paid ($) 866.11 865.34 864.57 863.79 863.01 862.22 861.43 860.63 859.83 859.03 858.22 857.40
Total Interest ($) 11317.84 12183.18 13047.75 13911.54 14774.55 15636.77 16498.20 17358.84 18218.67 19077.69 19935.91 20793.31
Balance ($) 148344.44 148211.83 148078.45 147944.28 147809.34 147673.61 147537.08 147399.76 147261.64 147122.71 146982.97 146842.42
Month
Year 4
2028 5
2028 6
2028 7
2028 8
2028 9
2028 10
2028 11
2028 12
2028 1
2029 2
2029 3
2029
Payment ($) 997.95 997.95 997.95 997.95 997.95 997.95 997.95 997.95 997.95 997.95 997.95 997.95
Principal Paid ($) 496.58 499.47 502.39 505.32 508.27 511.23 514.21 517.21 520.23 523.27 526.32 529.39
Interest Paid ($) 501.38 498.48 495.57 492.63 489.69 486.72 483.74 480.74 477.72 474.69 471.64 468.57
Total Interest ($) 175960.39 176458.87 176954.44 177447.07 177936.76 178423.48 178907.22 179387.96 179865.68 180340.37 180812.01 181280.57
Balance ($) 85453.54 84954.06 84451.68 83946.36 83438.09 82926.86 82412.65 81895.43 81375.20 80851.94 80325.62 79796.23
Notice that in Year 1 you only decrease your principle by $2000? You will be paying about $10,000 in interest. The following year it gets a bit better and then by year 20 for example, most of your money is going towards the principle.