Tithing is simple on a paycheck: 10% off the top, move on. Tithing on investment gains is where Christians get confused, because the math is not obvious and good people disagree about what counts as "increase."

Here is my honest take, with real numbers so you can decide what works for your conscience.

The Core Question

The biblical case for tithing comes from Leviticus, Deuteronomy, and Malachi, where the tithe is described as 10% of the "increase" or "produce" from the land. Abraham tithed to Melchizedek (Genesis 14:20) before the law. Jesus affirmed tithing in Matthew 23:23 while criticizing Pharisees for neglecting weightier matters.

When the Old Testament talks about "increase," it is describing crops, livestock, and income that came in during the year. Modern investment gains did not exist in that economic context, so we are applying a principle to a situation the text does not directly address.

Three main positions Christian financial teachers take on tithing investment gains:

Tithe on realized gains only (when you sell)
Tithe on all gains including unrealized paper gains
Tithe only on income received (dividends and interest), not on price appreciation

Let me walk through each one.

Position 1: Tithe on Realized Gains

Under this view, you owe 10% when you actually sell a position and receive cash. If you buy a stock for $10,000 and it grows to $18,000, you owe nothing until you sell. When you sell for $18,000, you owe 10% of the $8,000 gain, so $800 goes to church.

This is the most common Christian practice because it mirrors how the IRS taxes capital gains. You only pay when you realize the gain. Money that is still at risk in the market has not become "increase" yet because you could lose it all tomorrow.

The pros: simple, matches tax treatment, does not drain cash flow for gains you have not actually received.

The cons: creates a potential disconnect if you hold investments for decades. An investor who buys Apple in 2010 and never sells has technically seen huge "increase" but has never tithed on any of it.

Position 2: Tithe on All Gains Yearly

Under this stricter view, you calculate your portfolio value on December 31 and compare it to January 1 of the same year. The difference is your "increase" for the year, and you tithe 10% regardless of whether you sold anything.

Example:

January 1 portfolio value: $150,000
December 31 portfolio value: $168,000
Increase: $18,000
Tithe owed: $1,800

This view treats unrealized gains as real blessings from God that deserve a tithe now. Some Christian financial teachers, notably from the stricter tithing traditions, recommend this approach.

The pros: honors the principle of tithing on the firstfruits of any increase immediately. Aligns with the view that all wealth is God's regardless of whether it is liquid.

The cons: requires you to come up with cash to tithe on gains that are locked in investment accounts. If your IRA grows $10,000 but you cannot touch it without penalty, where does the $1,000 tithe come from? Also, if the market drops the following year, are you owed a refund?

Position 3: Tithe on Income Received Only

Under this narrower view, you tithe only on dividends, interest, and other income that hits your account during the year. Price appreciation is not "increase" until you actually receive it in a form you can spend.

Example:

Dividends received during the year: $2,400
Tithe owed: $240
Capital gains on a $150K portfolio that grew to $168K: no tithe (not received)

Some Christians extend this to also tithe on realized gains when you sell (making it a hybrid of Positions 1 and 3). This is probably the most defensible position for long-term investors with tax-advantaged retirement accounts.

Which View Is Right?

I am not going to pretend there is one obviously correct answer. Each has defenders among serious Christians.

Practical advice: if you are building wealth for the long term in retirement accounts, Position 1 or Position 3 is most workable because you literally cannot access the money to tithe without triggering tax penalties. If you are an active trader taking profits regularly, Position 1 makes the most sense because each sale creates real cash you can give.

If your conscience is troubled by Position 3, go with Position 2 and just accept that some years you will write larger checks. God cannot outgive you anyway.

Worked Example: The Peterson Family

Dave and Lisa Peterson have a household income of $145,000, plus they actively invest in a taxable brokerage account. Here is their 2026 investment activity:

Starting brokerage account value: $80,000
Ending brokerage account value: $92,000
Dividends received: $1,800 (reinvested)
Stocks sold during the year: $15,000 sale proceeds, cost basis $11,000, so $4,000 realized gain
New cash contributions: $6,000

They already tithe 10% of their $145K income ($14,500 to church). The question is what additional investment tithing looks like.

Using Position 1 (realized gains only)

Realized gain: $4,000
Extra tithe: $400
Total giving for year: $14,900

Using Position 2 (all gains)

Ending value minus starting value minus contributions = $92,000 - $80,000 - $6,000 = $6,000 in gains (including reinvested dividends)
Extra tithe: $600
Total giving for year: $15,100

Using Position 3 (income only plus realized)

Dividends: $1,800 + realized gain $4,000 = $5,800
Extra tithe: $580
Total giving for year: $15,080

The differences are not dramatic at this scale, but they accumulate over decades.

Retirement Account Gains: Extra Wrinkle

If your investments are inside a traditional 401(k) or traditional IRA, you have not paid tax on the original contribution. When you pull the money out in retirement, the IRS taxes the whole withdrawal as income. Some Christians argue you should tithe on the full withdrawal amount in retirement because you did not tithe on the contribution going in.

Example: a retiree pulls $40,000 from a traditional IRA in retirement. They tithe 10% = $4,000 to church on that withdrawal because the original $40K represented tax-deferred income.

For a Roth IRA, you already tithed (and paid tax) on the contribution. You do not owe tithe on the Roth withdrawal in retirement because the increase was already tithed on at the time of contribution (if you were doing it that way).

What About Losses?

If your portfolio drops $10,000 in a year, do you get a "negative tithe"? No. Tithing is not a net-of-loss calculation. You tithe on increase when it happens. Losses are absorbed.

However, some Christians practice a rolling year or trailing calculation where they only count net gains over multiple years. This is more art than science. Do what your conscience supports.

Practical Systems

Set up a "giving account" that you fund as gains come in. When you sell a stock for a $5,000 profit, immediately transfer $500 (or whatever your tithe percentage is) into the giving account. This keeps you from spending gains before you tithe on them and makes the calculation automatic.

If you use a spreadsheet or Mint-style tracker, add a "giving owed" column tied to gains. Update monthly.

Some Christians prefer to tithe once a year in December or January, calculating the full year at once. Others tithe monthly. Both work. Pick a rhythm.

Giving Appreciated Stock Directly

One tax-smart move: instead of selling a stock, paying capital gains tax, and then giving cash, give the appreciated stock directly to your church or a donor-advised fund. You avoid the capital gains tax entirely and still get a charitable deduction for the full market value.

Example: $10,000 of stock with a $3,000 cost basis.

Sell and tithe: you pay $1,050 capital gains tax, tithe $1,000, church gets $1,000, you keep about $7,950
Donate directly: church gets $1,000 market value, you pay $0 capital gains tax, you get a $1,000 charitable deduction

You come out ahead either way, but the direct donation is more efficient and gives the church the same amount. Most churches can accept stock donations through their finance office or a brokerage account.

Your Next Steps

Decide which of the three positions best fits your conscience and stick with it consistently. Set up a tracking system (spreadsheet, separate account, or monthly review) so gains do not slip through the cracks. If you have large unrealized gains in a taxable account, consider donating stock directly to maximize your giving impact. Talk to your pastor or a Christian financial counselor if you are genuinely stuck between positions.

God does not measure your stewardship by the exact formula you use. He measures your heart and faithfulness. Pick a system, be honest, and do not let perfect be the enemy of good.

Tithing on Capital Gains: The Christian Investor's Math