My 2015 AGI is going to be about 2.5x my 2014 AGI, some of that is going to be 1099 income, so I am trying to figure out my estimated quarterly tax payments. In filling out the 2015 estimated tax worksheet, I see that line 14c (required annual payment to avoid a penalty) is the smaller of my tax liability for 2015 * 90% or my required annual payment based on prior year's tax (line 63 on my 2014 1040). Because my income this year is so much different than my income last year, lines 14a and 14b are very different, but when I follow the worksheet and take the lower of the two numbers (my 2014 tax liability) and subtract my expected income tax withheld for 2015, it is a negative number, suggesting that I do not need to make estimated tax payments.

My question is, should I just start making estimated tax payments based on my expected 2015 tax liability (and will I be penalized if I do not do so?) or can I just wait until the end of the year because my total anticipated income tax withholding from 2015 is more than my total tax liability in 2014?

Basically, quarterly estimated tax is the method used to pay tax on income that is not subject to withholding. This includes income from self-employment, 1099,interest, dividends, alimony, rent, gains from the sale of assets, prizes and awards. You also may have to pay estimated tax if the amount of income tax being withheld from your salary, pension, or other income is not enough. If you did not pay enough tax throughout the year, either through withholding or by making estimated tax payments, you may have to pay a penalty for underpayment of estimated tax. Generally, most taxpayers will avoid this penalty if they owe less than $1K in tax after subtracting their withholdings and credits, or if they paid at least 90% of the tax for the current year,2015, or 100% of the tax shown on the return for the prior year, 2014, whichever is smaller. If AGI is more than $150K ($75K if married filing a separate return) in the prior tax year:The required payment is the lesser of 90 % of their tax for 2015 or 110 %of their tax for 2014.However, if your income is received unevenly during the year, you may be able to avoid or lower the penalty by annualizing your income and making unequal payments. Use Form 2210. You need to follow the process outlined on Form 2210 to determine whether you owe a penalty.To annualize your income to pay estimated taxes you have to monitor your income and expenses during the year and base your estimated payments on actual income rather than on estimates.
Please refer to Worksheet 2-9.2015 Annualized Estimated Tax Worksheet

Publication 505 (2015), Tax Withholding and Estimated Tax

I guess you go thru the instructions

Right, I get all that. My question is: Since my total tax owed in 2014 is going to be so much lower than my estimated tax owed this year in 2015 due to my increase in income this year. Even though I will owe more than 1000 dollars in taxes if I don't pay estimated taxes, will I avoid the penalty because my total tax with-holding in 2015 is greater than my total tax liability in 2014?...meaning I will have already paid much more than 100% of my 2014 taxes for this current year 2015.