An important element to consider is what other factors could decrease the size of your estate. At death, any outstanding debts you may have can contribute to estate shrinkage. Other items that can contribute to estate shrinking are funeral expenses, other administrative expenses and taxes.

You may also suffer a disability or an illness that may require long-term medical care, which may deplete assets during your lifetime. Your estate should have enough available cash to cover these costs so your heirs won't need to liquidate assets to pay them.

Based on your current situation, you may think the size of your estate may be significant. If you don't consider and prepare for some of life's unexpected possibilities, your heirs may end up with far less than you intended. Thinking about the unexpected includes providing a means that can help you ensure an inheritance for your successors.